In this paper, a CFD tool – Ansys Fluent 17.2 was applied to obtain a 3-D operational model of a 200 td-1 pilot-scale gasifier that was tested in Japan. The gasifier is an up-flow co-current reactor comprising combustor and reductor separated by a throat. For the modelling procedure, the Eulerian-Lagrangian method has been used. Euler approach describes the gas phase processes, whereas Lagrange describes the solid phase. The aim of this paper is at first to compare simulation results of two turbulence-chemistry interaction procedures available in Ansys Fluent and their impact on coal gasification and secondly to compare obtained results with the experiment.
PL
W tej pracy zastosowano program CFD – Ansys Fluent 17.2, aby otrzymać model 3D pilotażowej zgazowarki MHI 200 t/d, która była testowana w Japonii. Jest to reaktor współprądowy typu up-flow zawierający komorę spalania oraz reduktor oddzielone od siebie przez gardziel. Do otrzymania modelu zastosowano podejście Lagrange’a-Eulera. Faza dyspersyjna opisywana jest metodą Lagrange’a, natomiast faza ciągła – gazowa metodą Eulera. Celem tego badania było porównanie dwóch modeli opisujących wzajemne interakcje między kinetyką reakcji a turbulencją pod kątem całego procesu zgazowania oraz zestawienie uzyskanych wyników z wynikami eksperymentalnymi.
In this study a two-dimensional model of the coal gasification process in an entrained flow gasifier is investigated with a CFD software. Euler approach is used to simulated gas phase while the Lagrangian one is used to describe the solid phase. The current paper is focused on the importance of the gas phase simulation on the gasification model performance. Eddy dissipation concept is applied to simulate homogenous phase reactions a turbulence-chemistry interaction. Other available models have also been mentioned. Global reaction mechanism have been used initially. Consecutively the detailed GRI-Mech 1.2 Mechanism was implemented. GRI-Mech 1.2 Mechanism used in this study includes 176 homogenous embedded reactions and additional 3 heterogeneous reactions. The results of calculations obtained with both mechanisms exhibit good compatibility.