A 1.5D model of a complex geometry laboratory scale fuidized bed clc equipment

Krzywański, Jarosław; Żyłka, Anna; Czakiert, Tomasz; Kulicki, K.; Jankowska, Sylwia; Nowak, Wojciech

doi:10.1016/j.powtec.2016.09.041

Cited by 41 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The knowledge concerning CFB systems relied mostly on experimental studies but in recent years researchers have focused on improving CFB efficiency by utilizing the capabilities of numerical methods. With the rapid development of high performance computers, various techniques such as artificial intelligence including neurocomputing and fuzzy logic approach [3][4][5][6][7] were used in CFB modelling [8,9] but Computational Fluid Dynamics (CFD) turned out to be one of the best tools in such research and plays an important role in the design and optimization of industrial systems [10]. A common challenge for CFD is the expensive computational cost in terms of time required to reach a converged solution.…”

Section: Fig 1 Schematic Diagram Of Clc (O -Oxygen Oc -Oxygen Carrmentioning

confidence: 99%

Polyhedral meshing as an innovative approach to computational domain discretization of a cyclone in a fluidized bed CLC unit

Sosnowski

Gnatowska

2017

E3S Web Conf.

View full text Add to dashboard Cite

Abstract. Chemical Looping Combustion (CLC) is a technology that allows the separation of CO2, which is generated by the combustion of fossil fuels. The majority of process designs currently under investigation are systems of coupled fluidized beds. Advances in the development of power generation system using CLC cannot be introduced without using numerical modelling as a research tool. The primary and critical activity in numerical modelling is the computational domain discretization. It influences the numerical diffusion as well as convergence of the model and therefore the overall accuracy of the obtained results. Hence an innovative approach of computational domain discretization using polyhedral (POLY) mesh is proposed in the paper. This method reduces both the numerical diffusion of the mesh as well as the time cost of preparing the model for subsequent calculation. The major advantage of POLY mesh is that each individual cell has many neighbours, so gradients can be much better approximated in comparison to commonly-used tetrahedral (TET) mesh. POLYs are also less sensitive to stretching than TETs which results in better numerical stability of the model. Therefore detailed comparison of numerical modelling results concerning subsection of CLC system using tetrahedral and polyhedral mesh is covered in the paper.

show abstract

Section: Fig 1 Schematic Diagram Of Clc (O -Oxygen Oc -Oxygen Carrmentioning

confidence: 99%

Polyhedral meshing as an innovative approach to computational domain discretization of a cyclone in a fluidized bed CLC unit

Sosnowski

Gnatowska

2017

E3S Web Conf.

View full text Add to dashboard Cite

show abstract

“…Furthermore, the rising velocity of gas bubbles is dependent on the bubble diameter. These correlations are described by the following formulas [3,15]: The comparison between experimentally determined and predicted by the model for bubble diameter and rising velocity of gas bubbles are shown in Figures 13-16. The calculated results do not exceed 10 % compared to the experimental data, for bubble diameter and velocity of a bubble rise.…”

Section: Bubble Diameter and Rising Velocity Of Gas Bubblesmentioning

confidence: 99%

“…The successfully validated mathematical model allows to determine the influence of the superficial gas velocity on the following basic dynamic parameters of a CLC process [15]:…”

Section: Empirical Models For Basic Dynamic Parameters In Clc Processmentioning

confidence: 99%

Numerical simulations of fluidization dynamics in a hot model of a CLC process

et al. 2017

View full text Add to dashboard Cite

Abstract. Chemical Looping Combustion (CLC) is one of the most promising alternatives for solid fuel combustion. CO2 concentration in the exhaust gas is high in CLC technology which enables high efficiency of CO2 capture from flue gas. The use of solid oxygen carriers is a characteristic feature of a CLC process. Oxygen carriers are mainly metal oxides which are characterized by high oxygen transfer capacity and high mechanical resistance. Since the CLC technology is not sufficiently recognized due to its complexity the development of models with real conditions of the CLC equipment is of practical significance. The paper presents numerical simulations of the dynamic fluidized bed for Chemical Looping Combustion using CeSFaMB software. The model was validated on the basis of the results obtained from experiments, which were carried out on the Fluidized-Bed Chemical-Looping-Combustion of Solid-Fuels (FB-CLC-SF) unit. The studies were conducted in air atmosphere at temperature of 850°C. The validation of the 1.5D model showed that the maximum relative error between experiment and simulations results does not exceed 12%.

show abstract

“…Abdelmotalib et al remarked that due to very complicated processes, which occur in the fluidized bed combustors, it is difficult to cover all aspects of heat transfer [ 9 ]. Therefore some additional, auxiliary data, e.g., to adjust parameters or to solve complex differential equations are necessary, and even other assumptions should be made to get a trackable solution [ 33 , 34 , 35 , 36 , 37 , 38 ]. As an example, Zhou et al pointed out that simulations conducted on the platform of FLUENT 12 software with three processors parallel for 70 s with the number of meshes nearly 8500 costs nearly 60 days [ 15 , 39 ].…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Performance in a Superheater of an Industrial CFBC Using Fuzzy Logic-Based Methods

Krzywański

2019

Entropy

View full text Add to dashboard Cite

The heat transfer coefficient in the combustion chamber of industrial circulating flidized bed (CFB) boilers depends on many parameters as it is a result of multifactorial mechanisms proceeding in the furnace. Therefore, the development of an effective modeling tool, which allows for predicting the heat transfer coefficient is interesting as well as a timely subject, of high practical significance. The present paper deals with an innovative application of fuzzy logic-based (FL) method for the prediction of a heat transfer coefficient for superheaters of fluidized-bed boilers, especially circulating fluidized-bed combustors (CFBC). The approach deals with the modeling of heat transfer for the Omega Superheater, incorporated into the reaction chamber of an industrial 670 t/h CFBC. The height above the grid, bed temperature and voidage and temperature, gas velocity, and the boiler’s load constitute inputs. The developed Fuzzy Logic Heat (FLHeat) model predicts the local overall heat transfer coefficient of the Omega Superheater. The model is in good agreement with the measured data. The highest overall heat transfer coefficient is equal 220 W/(m2K) and can be achieved by the SH I superheater for the following inputs l = 20 m, tb = 900 °C, v = 0.95, u = 7 m/s, M-C-R = 100%. The proposed technique is an effective strategy and an option for other procedures of heat transfer coefficient evaluation.

show abstract

A 1.5D model of a complex geometry laboratory scale fuidized bed clc equipment

Cited by 41 publications

References 18 publications

Polyhedral meshing as an innovative approach to computational domain discretization of a cyclone in a fluidized bed CLC unit

Polyhedral meshing as an innovative approach to computational domain discretization of a cyclone in a fluidized bed CLC unit

Numerical simulations of fluidization dynamics in a hot model of a CLC process

Heat Transfer Performance in a Superheater of an Industrial CFBC Using Fuzzy Logic-Based Methods

Contact Info

Product

Resources

About