Dynamic simulation of fluidized bed combustors and its validation against measurements

2001-01-01
Selçuk, Nevin
Degirmenci, E
A dynamic mathematical model of a continuous atmospheric bubbling fluidized bed combustor (ABFBC) has been developed on the basis of first principles and used to correlate data from a pilot-scale combustor, The model accounts for bed and freeboard hydrodynamics, volatiles release and combustion, char particles combustion and their size distribution, and heat transfer. The solution procedure of dynamic model employs method of lines (MOL) approach for the solution of the governing nonlinear partial differential equations. The initial conditions required for each sub-model was provided from the simultaneous solution of governing equations of dynamic model with all temporal derivatives set to zero. Predictive accuracy of both steady state and dynamic models was assessed by applying it to the prediction of the behavior of METU 0.3 MW ABFBC Test Rig, and comparing their predictions with measurements taken on the same rig at steady state and transient conditions. Transient data were obtained by imposing changes to coal and air flow rates and measuring corresponding changes in oxygen and carbon monoxide concentrations at the exit of freeboard and in temperatures along the combustor against time. Comparisons of measurements and predictions chow that the predictions of the model are physically correct and agree well with the measurements.
COMBUSTION SCIENCE AND TECHNOLOGY

Suggestions

Experimental research on in-tube condensation under steady-state and transient conditions
Tanrikut, A; Yesin, O (2005-01-01)
In this research study, in-tube condensation in the presence of air was investigated experimentally at a heat exchanger of countercurrent type for different operating conditions. The test matrix for the steady-state condition covers the range of pressures P = 1.8 to 5.5 bars, vapor Reynolds numbers Re, = 45 000 to 94 000, and inlet air mass fraction values Xi = 0 to 52%. The effect of air manifests itself by a reduction in the local heat flux and the local heat transfer coefficient. The local heat transfer ...
Terahertz Transmission Through Patterened Vanadium Oxide Thin Films on Dielectric Substrates
AKKAYA, MAHİNUR; Demirhan, Y.; Yuce, H.; Aygun, G.; Ozyuzer, L.; SABAH, CUMALİ; Altan, Hakan (SCITEPRESS, AV D MANUELL, 27A 2 ESQ, SETUBAL, 2910-595, PORTUGAL; 2017-03-01)
Patterned and unpatterned films of vanadium oxide grown on dielectric substrates such as fused silica and sapphire were grown and analysed by varying the temperature using terahertz time domain spectroscopy. After investigating the critical transition temperature near 340K, a well-known cross-shaped pattern was studied to observe any resonances upon transmission. Due to the poor conductivity of the films the frequency selective nature of the structure was not observed, however an etalon effect could be seen...
Thermal characterization and gasification kinetics of thrace-saray region coal
Yıldırım, Betül; Kök, Mustafa Verşan; Department of Petroleum and Natural Gas Engineering (2015)
In this thesis being up as-received and washed and dried, two different coal samples from Saray-Edirkoy field were experimented in order to determine effects of different variables as coal type, heating rate, gas flow rate, isothermal duration, gasifying medium, and final gasification temperature, on isothermal gasification profiles of the coal samples. In the scope of this study, heating rate was changed in the range of 20-50oC/min as 20, 30, 40 and 50oC/min whereas two different gas flow rate values as 60...
Comparative kinetic analysis of raw and cleaned coals
Ozbas, K.E.; Kök, Mustafa Verşan; Hicyilmaz, C. (2002-09-24)
In this research, thermogravimetry (TG/DTG) was used to determine the kinetic analysis of different coals and effect of cleaning process on kinetic parameters of raw and cleaned coal samples from Soma, Tuncbilek and Afsin Elbistan regions. Kinetic parameters of the samples were determined using Arrhenius and Coats and Redfern kinetic models and the results are discussed.
Transient behavior of a cylindrical adsorbent bed during the adsorption process
SOLMUŞ, İsmail; Yamali, Cemil; Yıldırım, Cihan; BİLEN, Kadir (2015-03-15)
A transient two dimensional local thermal non-equilibrium model is developed to investigate the influences of heat transfer and operating parameters on the dynamic behavior of a cylindrical adsorbent bed during the adsorption process. Local volume averaging method is used to drive the macro scale governing conservation equations from the micro scale ones. In the model, linear driving force model and Darcy's equation are considered to account for the resistances to internal and external mass transfer, respec...
Citation Formats
N. Selçuk and E. Degirmenci, “Dynamic simulation of fluidized bed combustors and its validation against measurements,” COMBUSTION SCIENCE AND TECHNOLOGY, pp. 1–27, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/29860.