CFD studies of dual circulating fluidized bed reactors for chemical looping combustion processes

Multi-scale simulation of chemical looping combustion in dual circulating fluidized bed

“…The governing equations mainly include continuity equations, momentum conservation equations, species transport equations and energy conservation equations. Detailed descriptions of the model can be found in Wang et al [20].…”

“…Following the previous investigation of the mesh independence [19,20], the grid sizes of 5 Â 10 mm and 10 Â 10 mm are used for the reactors and other components respectively. The model is implemented on the basis of the M-FIX program, which is an open-source CFD code written in FORTRAN to describe the multiphase flow with inter-phase exchanges.…”

“…The results revealed that the effect of internal loop was enhanced when fluidization velocities were increased in reactors. Wang et al [19,20] investigated the flow and reactive characteristic for the CLC process in the DCFB system by means of CFD modeling, where a cluster structure-dependent (CSD) drag model was used to consider the cluster impact. From the simulated results, we can find that there was an improvement of the predictions in some extent.…”

Three-dimensional full loop simulation of solids circulation in an interconnected fluidized bed

“…Some efforts have been carried out on the CFD simulation of chemical looping combustion processes [10,[16][17][18][19][20][21][22][23][24][25][26][27][28][29]. However, only a few investigations have been focused on the full loop simulation of the interconnected fluidized bed, due to the complexities in geometry and flow physics, which requires large computational resources [1,28].…”

Approaching virtual process engineering with exploring mesoscience

“…The model has also been subjected to extensive tests from outside and to various modifications to meet the requirements of the specific problems they studied. It has been modified (i) to simulate CFB combustors [114,115], calcium looping for CO 2 capture in a lignite fired power plant [116], CFB carbonator [117] and gas desulfurization in a CFB riser [118]; (ii) to address the anisotropic characteristics of EMMS drag model [119]; (iii) to test the effects of using different particle cluster size correlations [120,121]; (iv) to model the effective interphase drag force of bubbling fluidization [122][123][124]; (v) to formulate an EMMS drag model that is conceptually consistent with the so-called type A two-fluid model and its applications [125][126][127][128][129][130]; (iv) to formulate another version by assuming the particle in dilute phases are in dilute limit and the particles in dense phase satisfy the Richardson-Zaki correlation [131,132]. Recent studies have shown that the EMMS drag model can also be used in Eulerian-Lagrangian simulations [133][134][135][136][137].…”