NUMERICAL SIMULATION OF A SLUGGING FB GASIFIER HYDRODYNAMICS, USING DDPM, DEM AND TFM APPROACHES
This work focuses on the 3D CFD isothermal simulation of a 100 kWth air-blown atmospheric circulating fluidized bed gasifier, operating in the slugging regime.Three different computing methodologies are applied for solving the dense gas-solid flow, i.e., i) the conventional two-fluid model (TFM) based on the Eulerian approach, ii) the Discrete Element Method (DEM) and, iii) a new promising approach, the Dense Discrete Phase Model (DDPM).The applied grid for all cases consists of 49332 tetrahedral elements.In the present study, the particles simulated have a mean diameter of 600 μm and their density is 2650 kg/m3.Simulation results are averaged over a time period of approximately 15 seconds and the induced pressure profile is compared against corresponding experimental data, measured at the CPERIs gasifier.In order to decrease the computational cost for the DEM approach, the solid particles are tracked in parcels.Three different number of particles per parcel are tested, i.e.60, 120 and 240.The comparison with experimental data for pressure distribution revealed that the DEM test case with 120 particles per parcels is the optimum model formulation in terms of computational cost and accuracy.In the case of the DDPM model this value is applied.Compared to the Euler and DEM approaches, the DDPM method is more efficient in terms of computational cost, although it has a moderate accuracy.Finally, the results of DEM and DDPM agree well with the slugging regime, where large pressure fluctuations are expected.The model adopting the TFM formulation failed to reproduce the slugging regime fact that is mainly attributed to the stress tensor and solids wall boundary condition applied.
Myrto Zeneli Nikos Nikolopouios Aristeidis Nikolopoulos Christos Christodoulou Kyriakos Panopoulos Panagiotis Grammelis Emmanuel Kakaras
Chemical Process and Energy Resources Institute,Centre for Research and Technology Hellas (CERTH/CPE Chemical Process and Energy Resources Institute,Centre for Research and Technology Hellas (CERTH/CPE
国际会议
The 11th International Conference on Fluidized Bed Technology(CFB-11)(第十一届流化床技术国际会议)
北京
英文
407-412
2014-05-14（万方平台首次上网日期，不代表论文的发表时间）