CFD Applications for Coal/Air Balancing in Power Plants

2003 ◽  
Author(s):  
Sowjanya Vijiapurapu ◽  
Jie Cui ◽  
Sastry Munukutla
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Drop ◽  
Power Plants ◽  
Air Flow ◽  
New Method ◽  
Industry Practice ◽  
Clean Air ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Applications

A new method for balancing coal / air flow to individual burners connected to a mill in a pulverized coal fired unit was proposed. A generalized calculation procedure based on this method was developed for sizing the orifices needed for balancing the coal / air flow. Efficient use of commercially available computational fluid dynamics (CFD) software was suggested for the calculation of the pressure drop in pipes with unclear specifications of geometries. The current industry practice is to balance the clean air flow and accept the resulting imbalance in the coal / air flow. By this new method the clean-air flow would be unbalanced in a tailored manner so that balanced coal / air flow would result. In order to implement this new method the power plants would still have to conduct clean air tests only.

Construction Ventilation Scheme Optimization of Underground Main Powerhouse Based on CFD

2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Air Flow ◽  
Scheme Optimization ◽  
Pressure Distributions ◽  
Air Volume ◽  
Computational Fluid Dynamics Cfd ◽  
Traditional Construction ◽  
Ventilation Scheme

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.

scholarly journals Propagation of Input Uncertainty in Presence of Model-Form Uncertainty: A Multifidelity Approach for Computational Fluid Dynamics Applications

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Jian-Xun Wang ◽  
Christopher J. Roy ◽  
Heng Xiao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Parameter Space ◽  
Uncertainty Propagation ◽  
High Fidelity ◽  
Sampling Errors ◽  
Uncertainty Distribution ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Applications

Proper quantification and propagation of uncertainties in computational simulations are of critical importance. This issue is especially challenging for computational fluid dynamics (CFD) applications. A particular obstacle for uncertainty quantifications in CFD problems is the large model discrepancies associated with the CFD models used for uncertainty propagation. Neglecting or improperly representing the model discrepancies leads to inaccurate and distorted uncertainty distribution for the quantities of interest (QoI). High-fidelity models, being accurate yet expensive, can accommodate only a small ensemble of simulations and thus lead to large interpolation errors and/or sampling errors; low-fidelity models can propagate a large ensemble, but can introduce large modeling errors. In this work, we propose a multimodel strategy to account for the influences of model discrepancies in uncertainty propagation and to reduce their impact on the predictions. Specifically, we take advantage of CFD models of multiple fidelities to estimate the model discrepancies associated with the lower-fidelity model in the parameter space. A Gaussian process (GP) is adopted to construct the model discrepancy function, and a Bayesian approach is used to infer the discrepancies and corresponding uncertainties in the regions of the parameter space where the high-fidelity simulations are not performed. Several examples of relevance to CFD applications are performed to demonstrate the merits of the proposed strategy. Simulation results suggest that, by combining low- and high-fidelity models, the proposed approach produces better results than what either model can achieve individually.

Good modelling practice in applying computational fluid dynamics for WWTP modelling

2015 ◽  
Vol 73 (5) ◽  
pp. 969-982 ◽  
Author(s):  
Edward Wicklein ◽  
Damien J. Batstone ◽  
Joel Ducoste ◽  
Julien Laurent ◽  
Alonso Griborio ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Working Group ◽  
Companion Paper ◽  
Cfd Modelling ◽  
Cfd Models ◽  
Water Association ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Applications ◽  
International Water

Computational fluid dynamics (CFD) modelling in the wastewater treatment (WWT) field is continuing to grow and be used to solve increasingly complex problems. However, the future of CFD models and their value to the wastewater field are a function of their proper application and knowledge of their limits. As has been established for other types of wastewater modelling (i.e. biokinetic models), it is timely to define a good modelling practice (GMP) for wastewater CFD applications. An International Water Association (IWA) working group has been formed to investigate a variety of issues and challenges related to CFD modelling in water and WWT. This paper summarizes the recommendations for GMP of the IWA working group on CFD. The paper provides an overview of GMP and, though it is written for the wastewater application, is based on general CFD procedures. A forthcoming companion paper to provide specific details on modelling of individual wastewater components forms the next step of the working group.

Flow Simulations in Packed Beds by a Coupled DEM and CFD Approach

2012 ◽  
Author(s):  
Xiang Zhao ◽  
Trent Montgomery ◽  
Ping Lu ◽  
Sijun Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Drop ◽  
Structural Parameters ◽  
Packed Beds ◽  
Local Behavior ◽  
Cfd Simulations ◽  
Flow Simulations ◽  
Packing Structure ◽  
Computational Fluid Dynamics Cfd

This paper presents flow simulations in packed beds by a coupled discrete element method (DEM) and computational fluid dynamics (CFD) approach. The realistic packing structure in packed beds is generated by DEM. Then the packing structure is imported into the CFD preprocessor to generate a mesh for flow simulations in packed beds. The subsequent CFD simulations are carried out. The predicted results reveal that not only the local behavior but also macroscopic quantities like the pressure drop depend remarkably on the local packing structural parameters, which is unable to be taken into account when using correlations with averaged values.

Numerical Investigation of Dusts Removal from Tramway Surface by Street Vacuum Sweeper

2011 ◽  
Vol 236-238 ◽  
pp. 1619-1622 ◽  
Author(s):  
Bo Fu Wu ◽  
Jin Lai Men ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Pressure Drop ◽  
Removal Efficiency ◽  
Pressure Drops ◽  
Operational Safety ◽  
Airflow Field ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

In order to enhance the operational safety of tram vehicle and reduce the wear of guide wheels mounted on the vehicle, it is necessary to remove particles such as dusts and silts from tramway surface. The aim of this paper is to evaluate the effectiveness of street vacuum sweeper for sucking up dusts from tramway surface. A numerical model was developed based on dusts removal process. Under different pressure drops across the pickup head of the street vacuum sweeper, the flow field and dusts removal efficiency were analyzed with computational fluid dynamics (CFD) method. The numerical results show that a higher pressure drop can improve the airflow field in the pickup head and results in higher dusts removal efficiency, but higher pressure drop definitely need more energy. Therefore, a balance should be taken into consideration.

scholarly journals Numerical Simulation of Single-Phase and Two-Phase Flows in Separator Vessels with Inclined Half-Pipe Inlet Device Applied in Reciprocating Compressors

2018 ◽  
Vol 8 (3) ◽  
pp. 2897-2900
Author(s):  
F. P. Lucas ◽  
R. Huebner
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Single Phase ◽  
Air Flow ◽  
Air Distribution ◽  
Two Phase ◽  
Computational Fluid Dynamics Cfd ◽  
Liquid Removal ◽  
Pipe Inlet

This paper aims to apply computational fluid dynamics (CFD) to simulate air flow and air flow with water droplets, as a reasonable hypothesis for real flows, in order to evaluate a vertical separator vessel with inclined half-pipe inlet device (slope inlet). Thus, this type was compared to a separator vessel without inlet device (straight inlet). The results demonstrated a different performance for the two types in terms of air distribution and liquid removal efficiency.

An Introduction to Computational Fluid Dynamics and Its Application in Microfluidics

2019 ◽  
pp. 50-78
Author(s):  
João Lameu da Silva Júnior
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Single Phase ◽  
Chemical Engineering ◽  
Numerical Technique ◽  
Quality Parameters ◽  
Flow In Porous Media ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Applications ◽  
Volume Method

The chapter aims to introduce the computational fluid dynamics (CFD). A review was provided, outlining its development and applications on chemical engineering and microfluidics. The fundamental points of the CFD, listing the advantages and precautions of this numerical technique were provided. The description of CFD methodology including the three essential stages (pre-processing, solving, and post-processing) was made. The fundamental transport equations—total mass (continuity), momentum, energy, and species mass balances—and the usual boundary conditions used in CFD were explained. The main approaches used in multicomponent single-phase flows, single-phase flow in porous media, and multiphase flows in microscale were detailed, as well as the numerical mesh types and its quality parameters. A brief introduction of finite volume method (FVM) used by most of the available CFD codes was also performed, describing the main numerical solution features. Finally, the conclusions and future prospects of CFD applications are exposed.

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