Numerical simulation of the flow and combustion processes in a three-dimensional, w-shaped boiler furnace

Fan, Jianren; Liang, Xiubo; Xu, Qianting; Zhang, X.Y.; Cen, Kefa

doi:10.1016/s0360-5442(97)00008-x

Cited by 44 publications

(24 citation statements)

References 5 publications

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“…Gas turbulence was specifically taken into account by the so-called realizable k À e model [25][26][27]. In the area close to the wall, where the flow is laminar, the standard wall function method was adopted and the particle trajectory model was chosen to simulate gas-solid two-phase flow.…”

Section: Mathematical Models and Calculation Methodsmentioning

confidence: 99%

Modeling the Occurrence and Methods of Reducing Thermal Deviations of Upper Furnace Heating Surfaces in a 1000 MW Dual Circle Tangential Firing Single Furnace Ultra-Supercritical Boiler

Liu

Sha

et al. 2014

Numerical Heat Transfer, Part A: Applications

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The FLUENT computational fluid dynamics software package was used to model outlet velocity and temperature inhomogeneity in a 1000 MW dual circle tangential firing single furnace ultra-supercritical boiler. These computations allowed a theoretical analysis of thermal deviations at the furnace outlet and suggested means of reducing such deviations. This work involved study of radiative and convective heat transfer of the upper furnace platen superheaters, the radiative-convective heating surfaces above the furnace nose and the convective heating surfaces in the horizontal flue. The results demonstrated that the radiant heat load of the heating surfaces of the platen superheaters is related to the sectional dimensions of the furnace and exhibits a bimodal distribution in the boiler modeled during this work. It was also determined that a large recirculation zone is formed in the central section of the horizontal flue owing to velocity superposition. After establishing the thermal load distribution characteristics and the causes of thermal deviations at the various heating surfaces, further modeling was performed to assess the extent to which thermal deviations could be reduced by decreasing residual rotation at the furnace outlet via horizontally swinging the over fire air (OFA). The effects of OFA swing angles on velocity and temperature inhomogeneity at the furnace outlet were subsequently analyzed, and an OFA swing of À10 was found to be optimal based on considerations of thermal deviations at the furnace outlet, the airflow field in the furnace, and safe operation of the boiler.

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Section: Mathematical Models and Calculation Methodsmentioning

confidence: 99%

Modeling the Occurrence and Methods of Reducing Thermal Deviations of Upper Furnace Heating Surfaces in a 1000 MW Dual Circle Tangential Firing Single Furnace Ultra-Supercritical Boiler

Liu

Sha

et al. 2014

Numerical Heat Transfer, Part A: Applications

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“…According to the difference of manufacturers, down‐fired boilers can be roughly divided into four categories which are separately the Foster Wheeler, the Bob Cock and Wilcox (B&W), the Stein, and the Mitsui Babcock Energy Limited (MBEL) down‐fired boiler. Among them, the Stein and MBEL down‐fired boiler adopt direct‐flow split pulverized‐coal burners .…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler

Zeng

Liu

et al. 2019

Asia-Pacific J Chem Eng

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Numerical simulations are carried out to investigate the influence of burner nozzle–organization–mode (N–O–M) on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler. Three typical N–O–Ms respectively designed with Mitsui Babcock Energy Limited (MBEL), fuel‐lean coal/air flow down‐setting (FD), and multi‐injection multistaging combustion (MIMSC) technology are studied, plus industrial‐size measurements on the original MBEL boiler. Vertical velocity attenuation index (η) and maximum dimensionless penetrating depth (γ) are introduced to estimate the transfer effect and penetrating capacity of pulverized coal/air flow. Results uncover that under the N–O–M based on MBEL technology, flow field and temperature field are deflective. η is 9.257. Under N–O–Ms based on FD and MIMSC technology, flow field and temperature field present obvious symmetry. η respectively are 4.365 and 2.921. γ are correspondingly about 0.8 and 1.36. Carbon content in fly ash and NOx emissions at furnace outlet are lowest (5.77% and 735.21 mg/m3 (O2 = 6%)) under the N–O–M with MIMSC technology. The bigger the η is, the worse penetrating characteristics of coal/air flow is, resulting in poor burnout of pulverized coal. Therefore, MIMSC technology is recommended for the boiler improvement, and η should be taken into account in the design of new down‐fired boiler N–O–Ms.

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“…Generally, the low NO x burner is one of the most effective methods used in the low NO x combustion technology. In recent decades, lots of experimental or numerical researches [3][4][5] have been conducted on the coal combustion boiler to investigate the flow field, coal combustion, and NO x emission. Compared with the expensive experiments, computational fluid dynamics (CFD) is an indispensable tool to optimize the low NO x technology.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on the flow, combustion, and NO_X emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler

Sun

Zhong

et al. 2016

Advances in Mechanical Engineering

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A three-dimensional numerical simulation was carried out to study the pulverized-coal combustion process in a tangentially fired ultra-supercritical boiler. The realizable k-e model for gas coupled with discrete phase model for coal particles, P-1 radiation model for radiation, two-competing-rates model for devolatilization, and kinetics/diffusion-limited model for combustion process are considered. The characteristics of the flow field, particle motion, temperature distribution, species components, and NO x emissions were numerically investigated. The good agreement of the measurements and predictions implies that the applied simulation models are appropriate for modeling commercial-scale coal boilers. It is found that an ideal turbulent flow and particle trajectory can be observed in this unconventional pulverized-coal furnace. With the application of over-fire air and additional air, lean-oxygen combustion takes place near the burner sets region and higher temperature at furnace exit is acquired for better heat transfer. Within the limits of secondary air, more steady combustion process is achieved as well as the reduction of NO x . Furthermore, the influences of the secondary air, over-fire air, and additional air on the NO x emissions are obtained. The numerical results reveal that NO x formation attenuates with the decrease in the secondary air ratio (g 2nd ) and the ratio of the additional air to the over-fire air (g AA / g OFA ) was within the limits.

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Numerical simulation of the flow and combustion processes in a three-dimensional, w-shaped boiler furnace

Cited by 44 publications

References 5 publications

Modeling the Occurrence and Methods of Reducing Thermal Deviations of Upper Furnace Heating Surfaces in a 1000 MW Dual Circle Tangential Firing Single Furnace Ultra-Supercritical Boiler

Modeling the Occurrence and Methods of Reducing Thermal Deviations of Upper Furnace Heating Surfaces in a 1000 MW Dual Circle Tangential Firing Single Furnace Ultra-Supercritical Boiler

Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler

Numerical investigation on the flow, combustion, and NO_X emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler

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Numerical simulation of the flow and combustion processes in a three-dimensional, w-shaped boiler furnace

Cited by 44 publications

References 5 publications

Modeling the Occurrence and Methods of Reducing Thermal Deviations of Upper Furnace Heating Surfaces in a 1000 MW Dual Circle Tangential Firing Single Furnace Ultra-Supercritical Boiler

Modeling the Occurrence and Methods of Reducing Thermal Deviations of Upper Furnace Heating Surfaces in a 1000 MW Dual Circle Tangential Firing Single Furnace Ultra-Supercritical Boiler

Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler

Numerical investigation on the flow, combustion, and NOX emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler

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Numerical investigation on the flow, combustion, and NO_X emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler