Dynamic CFD modeling evaluation of ash deposition behavior and morphology evolution with different tube arrangements

Mu, Lin; Miao, Hongchao; Zhao, Cheng; Zhai, Zhende; Shang, Yan; Yin, Huiming

doi:10.1016/j.powtec.2020.10.057

Cited by 19 publications

(3 citation statements)

References 44 publications

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“…It was seen that the staggered elliptical tube bundle can reduce both fouling and heat transfer abatement comparing with the aligned circular tube bundle [11]. The numerical results of Mu et al [12] using a dynamic ash deposition model also suggest an optimal shape and arrangement of tube bundles for reducing ash deposition. Zheng et al [13] studied the ash deposit growth on a single heat exchanger tube in a pilot-scale furnace using dynamic mesh morphing.…”

Section: Introductionmentioning

confidence: 90%

CFD modelling of biomass ash deposition under multiple operation conditions using a 2D mass-conserving dynamic mesh approach

Yang

Zhou

2022

Fuel

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Section: Introductionmentioning

confidence: 90%

CFD modelling of biomass ash deposition under multiple operation conditions using a 2D mass-conserving dynamic mesh approach

Yang

Zhou

2022

Fuel

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“…The cases with fouled tubes presented 7.91% higher deposition rates than what was observed for clean tubes. In addition, Mu et al [29] proposed a new CFD model to predict the morphological evolution of ash deposits on tube bundles and proved that an elliptical tube could reduce deposition efficiency. Despite these efforts, the dynamic deposition behavior of specific alkali-enriching coal ash particles under typical tube bundle conditions has not been examined, and the heat flux distribution among these tubes as a result of ash deposition has not been examined-both of which are, however, important for the design and operation of boilers burning high-sodium coal.…”

Section: Introductionmentioning

confidence: 99%

A Numerical Simulation Study into the Effect of Longitudinal and Transverse Pitch on Deposition of Zhundong Coal Ash on Tube Bundles

Guo,

Li,

Liang

et al. 2024

Processes

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In this paper, the dynamic deposition behavior of Na-enriching Zhundong coal ash on tube bundles with varying longitudinal and transverse pitches was numerically studied. By using a modified critical viscosity model, an improved CFD deposition model has been established and key parameters, including deposit mass and morphology, particle trajectories and impaction and sticking probabilities, as well as the heat flux distribution, have been analyzed. The results show that the ash deposited on tubes in the first row is, respectively, 1.74 and 3.80 times higher than that on the second and third rows, proving that ash deposition in the downstream is lessened. As the longitudinal pitch increased from 1.50 D to 2.50 D, deposit mass in the downstream increased two times, suggesting that an increase in longitudinal pitch would aggravate ash deposition. The effect of transverse pitch, however, with the least deposit propensity at St/D = 1.75, is non-linear due to the joint effect of adjacent tubes and walls in affecting particle trajectory. In addition, due to the non-uniform distribution of the deposit, heat flux across the tube is the smallest at the stagnation point but becomes six times higher at two sides and the leeward, which makes the thermal damage of these sides to be warranted as a practical concern.

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“…Previous studies have primarily concentrated on the processes of flow, heat transfer, and ash deposition in the RSC, − while the thermal deformation behavior has rarely been studied. However, in industrial operations, the thermal deformation of the top sealing structure causes local overtemperature and sealing looseness, leading to system shutdown in emergency cases, which directly impacts the safe and efficient operation of the gasification system.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of the Integral Thermal Deformation Behavior of a Radiant Syngas Cooler for an Entrained-Flow Gasifier

Zhang,

Xu,

Gong

et al. 2023

Ind. Eng. Chem. Res.

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A radiant syngas cooler (RSC) is an important device in the heat recovery type of entrained-flow gasifier that can effectively improve the energy utilization efficiency. In this work, a three-dimensional (3D) industrial RSC model is established. Heat transfer characteristics and integral thermal deformation behavior are studied by numerical simulation, combining the principle of fluid–structure coupling to explore the variation of integral thermal deformation under different operating conditions. The simulation results indicate that the setting of the radiation screen has different effects on the uneven heating of the membrane wall in the circumferential direction, varying with heights. An equivalent stress concentration area in the middle and upper parts under industrial constraints is shown on the cylinder membrane wall. The equivalent stress of the upper cone membrane wall surface exceeds the allowable stress of the material. The thermal deformation of the top sealing structure and the bottom is 45.6 mm and 64.5 mm, respectively. The upward movement of the fixed support reduces the thermal deformation of the top sealing structure while increasing the thermal deformation of the bottom. An increase in the inlet temperature causes an increase in the thermal deformation of the top sealing structure and the equivalent stress at the middle and upper parts of the cylinder membrane wall while having an insignificant impact on the thermal deformation of the bottom. The deposition of ash and slag reduces the thermal deformation of the top sealing structure and the total heat transfer rate of the cylinder membrane wall. With a slight effect on the total thermal deformation, increasing the slag thickness decreases the total heat transfer rate.

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Dynamic CFD modeling evaluation of ash deposition behavior and morphology evolution with different tube arrangements

Cited by 19 publications

References 44 publications

CFD modelling of biomass ash deposition under multiple operation conditions using a 2D mass-conserving dynamic mesh approach

CFD modelling of biomass ash deposition under multiple operation conditions using a 2D mass-conserving dynamic mesh approach

A Numerical Simulation Study into the Effect of Longitudinal and Transverse Pitch on Deposition of Zhundong Coal Ash on Tube Bundles

Numerical Simulation of the Integral Thermal Deformation Behavior of a Radiant Syngas Cooler for an Entrained-Flow Gasifier

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