TU BRAUNSCHWEIG

FLOREAN – Numeric Combustion Chamber Simulations

Firings

To further develop firings, the usage of simulations as opposed to expensive experiments is rising. For this reason the simulation program FLOREAN (FLOw and REAction) has been developed at this institute. FLOREAN is able to integrate the partial differential equations of the laws of conservation of energy (energy, momentum and mass) as well as the substances involved in the reactions (combustible, oxygen, exhaust gas components, contaminants). This is achieved by a numeric integration using the finite-volume method. The influence of turbulence on the transport processes is calculated through the k-e-turbulence model and the heat transfer is calculated with irradiation using a sechs-fluss Modell. There can be up to 1 million volume elements which need to be solved numerically through a linked system of 18 partial differential equations. This includes the reaction kinetics of the burnup. For these calculations the institute has SUN-Workstations at its disposal. To analyze the results extensive graphical programs are used. Among others this opens the possibility to output the progression of each individual parameter in unrestricted display sizes.

Fluidized bed firings

To help fluid mechanics and incinerations in fluidized bed firings, a simplified one-dimensional fluidized bed model has been developed, which for the first time takes grain size distribution into account. Furthermore a FLOREAN-based three-dimensional Euler-Lagrange-simulation program has been developed, in which the bed-material and coal are calculated using the Lagrangian method. These models provide spatial temperature, speed, concentration and porosity distribution, also used in following pollutant calculations.
The kinetics of the generation of pollutants and the involvement of pollutants into the fluidized bed are simulated with an adjusted kinetic model.

Thermal waste treatment

The institute is planning to expand the usage of FLOREAN for thermal waste treatment. Initial calculations of currents inside the radiation chamber of a waste incineration plant have been made. This allows to numerically calculate recommendations to improve incineration on the rack.

Slagging and pollution

While solid combustibles are incinerated, mineral components inside the thermal focal point of the firing are transformed into slag and ash. Due to this transformation-process slag and dirt may pollute the combustion chamber walls resulting in major problems while operating. FLOREAN is able to calculate coal particle trajectories, as well as the conversion processes on these trajectories, in a representable amount (several ten-thousands). This opens the possibility to predict the behavior of slagging and pollution more precisely.

Testbeispiele: (Vergleich mit analytischer Lösung bzw. Meßwerten)
 

 
Masse
Impuls
Energie
Turbulenz
Strahlung
Verbrennung
laminare Strömung im Rechteckkanal
X
X
       
turbulente Strömung im Rechteckkanal
X
X
 
X
   
Modell einer Tangentialfeuerung
X
X
 
X
   
heißer quer angeströmter Freistrahl
X
X
X
X
   
Ijmuiden-A1-Flamme Strahlbrenner
X
X
X
X
X
Steinkohle
Ijmuiden-Drallflamme (mit GT-Abgasen)
X
X
X
X
X
Steinkohle 
3 Partikelgrößen
Instituts-Versuchsstand Drallbrenner
X
X
X
X
X
Braunkohle
Brandversuchsstand
X
X
X
X
X
Gas
SNCR-Verfahren
X
X
X
X
X
 
Auftriebströmung Würfel
X
X
X
X
   

Auftragsrechnungen:
 

 
el. Leistung
(MW)
Kohle
Brenner
Feuerung
NOx
SO2
Bemerkungen
Deutschland
300
Braun
Tangential Strahlbrenner
X
 
Vergleich mit Messungen
Griechenland
300
Braun
Tangential Strahlbrenner
X
X
--"--
Griechenland
ca. 350
Braun
Tangential Strahlbrenner
X
X
--"--
Deutschland
600
Braun
Tangential Strahlbrenner
X
 
--"--
Verschlackung
Deutschland
350
Braun
Tangential Strahlbrenner
   
Brenneranstellwinkel
Verschlackung
Deutschland
350
(Öl)
nur natürliche Konvektion
beim Auskühlen
     
Deutschland
900
Braun
Tangential Strahlbrenner
X
 
ABL, Brenneranordnung
Deutschland
900
Braun
Tangential Strahlbrenner
     
Deutschland
ca. 550
Stein
Boxerfeuerung Drallbrenner
     
Japan
550
Stein
Eckenfeuerung Strahlbrenner
     
Deutschland
600
TBK
Tangential Strahlbrenner
X
 
Verschmutzung
Deutschland
ca. 150
Stein
Eckenfeuerung Drallbrenner
     
Frankreich
600
Stein
Eckenfeuerung Drallbrenner
X
   
China
600
Stein
Boxerfeuerung Drallbrenner
     
Griechenland
350
Braun
Tangential Strahlbrenner
   
TBK-Mitverbr.
Griechenland
350
Braun
Tangential Strahlbrenner
X
 
Verschlackung

Ansprechpartner:

Dr.-Ing. Horst Müller, e-mail:H.Mueller@tu-bs.de



  last changed 24.09.2014
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