Numerical study on heat and mass transfer characteristics in a randomly packed air cooling tower for large-scale air separation systems

Tan, Hongbo; Wen, Na; Ding, Zhi

doi:10.1016/j.ijheatmasstransfer.2021.121556

“…where c p is the specific heat of the particle material. q̇is the total particle heat transfer rate, which is given by = + + q q q q c f p dry (19) where qċ →ε is the heat transfer that occurs during the contact with other particles or walls, qḟ →p is the convective heat transfer between particle and fluid phase, qḋ ry is the latent heat of evaporation required to reduce the moisture content in the particle phase.…”

Section: 2mentioning

confidence: 99%

“…Cubero et al 18 adopted the Eulerian−Eulerian model to simulate a pilot-scale coal gasification fluidized bed. Tan et al 19 combined Eulerian, porous and heat and mass transfer models to establish a three-dimensional CFD simulation method for an industrial-scale air cooling tower.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Thermal Drying Process of Sludges Based on CFD-DEM

Gong

¹

,

Zhang

²

,

Ye

³

et al. 2023

Ind. Eng. Chem. Res.

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Sludge drying is a crucial part of the sludge treatment and disposal processes, while thermal drying has been a popular choice. In this work, the sludge thermal drying process is numerically simulated using a coupled computational fluid dynamics−discrete element method (CFD-DEM) approach. The CFD-DEM model describes the flow and heat transfer in the gas−solid system, while a mass transfer approach is embedded to describe the variation in the moisture content. First, a suitable numerical model to describe the sludge water removal process is developed based on physical experimental data. Quantitative comparisons with experimental data validate the predictive capability of the numerical model for the continuum gas flow field, as well as the sludge drying process. Then, five key parameters including velocity, temperature and humidity of the heat source, particle size, and sludge pile thickness are discussed to obtain the basic laws affecting the sludge drying process. The pilot dryer is subsequently simulated, and a simplified solution for industrial-scale simulation is proposed. All of the above work is supported by abundant experimental data to demonstrate the capability of the CFD-DEM model. Finally, based on more CFD-DEM simulation, the optimal operating conditions are determined with flexibility recommendations for dryer design summarized. This work contributes to an indepth understanding of sludge drying characteristics and also has important practical and theoretical engineering value.

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“…The conduction heat transfer in the cold box plays a dominant role [3,5,12]. Tan et al [13] and Xu et al [14]only used conduction heat transfer in the calculation and ignore radiation heat transfer to simplify the computation of storage time. However, Sharma et al [15] and Paquette et al [16] found that the radiation heat transfer in the cold box has a remarkable effect on the temperature in the box by adding aluminum foil to the inner wall of the cold box, when the temperature difference between inside and outside cold box is large.…”

Section: Introductionmentioning

confidence: 99%

Theoretical modeling and verification of storage time of cold box based on network method of radiation heat transfer

Fu

¹

,

Liu

²

,

Duan

³

et al. 2023

Numerical Heat Transfer, Part A: Applications

0

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The storage time of cold box is an important subject. At present, the research method of the storage time is mainly experiment, and the theoretical research is incomplete. Therefore, in this work, a theoretical modeling combined with a network method of radiation heat transfer, shape factor of heat conduction, and sensible heat of refrigerant was proposed to calculate the storage time of a cold box at various ambient temperatures and amounts of refrigerant. The experimental and simulation results were used to verify the theoretical modeling of the storage time.

show abstract

“…The conduction heat transfer in the cold box plays a dominant role [3,5,12]. Tan et al [13] and Xu et al [14]only used conduction heat transfer in the calculation and ignore radiation heat transfer to simplify the computation of storage time. However, Sharma et al [15] and Paquette et al [16] found that the radiation heat transfer in the cold box has a remarkable effect on the temperature in the box by adding aluminum foil to the inner wall of the cold box, when the temperature difference between inside and outside cold box is large.…”

Section: Introductionmentioning

confidence: 99%

Theoretical modeling and verification of storage time of cold box based on network method of radiation heat transfer

Fu

¹

,

Liu

²

,

Duan

³

et al. 2022

Preprint

0

View full text Add to dashboard Cite

The storage time of cold box is an important subject. At present, the research method of the storage time is mainly experiment, and the theoretical research is incomplete. Therefore, in this work, a theoretical modeling combined with a network method of radiation heat transfer, shape factor of heat conduction, and sensible heat of refrigerant was proposed to calculate the storage time of a cold box at various ambient temperatures and amounts of refrigerant. The experimental and simulation results were used to verify the theoretical modeling of the storage time. The influences of sensible heat of refrigerant and radiation heat transfer in the cold box were analyzed. The stability of the theoretical modeling was studied via simulation of the different cold box and refrigerant materials. The results of the accuracy of theoretical model confirmed that the maximum error between the theoretical and the experimental storage times is 8.45%, and error between the theoretical and the simulation results is 7.51%, indicating that the sensible heat of refrigerant and radiation heat transfer have big impacts on the storage time. The stability of theoretical model is confirmed under different box and refrigerant materials. The storage time model has stability on different box materials and refrigerant materials. The theoretical model can be severed as a fundamentally guidance for the cold box production design.

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Numerical study on heat and mass transfer characteristics in a randomly packed air cooling tower for large-scale air separation systems

Cited by 14 publications

References 29 publications

Numerical Investigation on Thermal Drying Process of Sludges Based on CFD-DEM

Numerical Investigation on Thermal Drying Process of Sludges Based on CFD-DEM

Theoretical modeling and verification of storage time of cold box based on network method of radiation heat transfer

Theoretical modeling and verification of storage time of cold box based on network method of radiation heat transfer

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