Acknowledgments

Sieniutycz, Stanisław; Szwast, Zbigniew

doi:10.1016/b978-0-12-813582-2.04001-5

Cited by 2 publications

(6 citation statements)

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“…Substituting q = U(T He − T) into Equations (29) and continuing to omit other items irrelevant to T He yields:…”

Section: The Optimal Control Formulationmentioning

confidence: 99%

“…Chen et al [72] also investigated t tion of carbon dioxide and hydrogen to synthesize olefins, and analyzed the effe actor structural parameters on specific EGRs; the specific EGR could be reduced by and 24.78% under the optimal catalyst bed density and pipe diameter, respective al. [73] studied the steam methane reforming reactor with hydrogen PRM as the zation goal, and obtained the optimal wall temperature distribution and inlet p Finite-time thermodynamics (FTT) has made significant progress in physics and engineering fields since the mid-1970 s [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33], and the aim is to reduce the irreversibility of systems under finite time and size constraints. The applications of FTT include the researches of optimal performances [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] and optimal configurations [51][52][53][54][55][56][57][58][59][60]...…”

Section: Introductionmentioning

confidence: 99%

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Minimization of Entropy Generation Rate in Hydrogen Iodide Decomposition Reactor Heated by High-Temperature Helium

Kong

Chen

Xia

et al. 2021

Entropy

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The thermochemical sulfur-iodine cycle is a potential method for hydrogen production, and the hydrogen iodide (HI) decomposition is the key step to determine the efficiency of hydrogen production in the cycle. To further reduce the irreversibility of various transmission processes in the HI decomposition reaction, a one-dimensional plug flow model of HI decomposition tubular reactor is established, and performance optimization with entropy generate rate minimization (EGRM) in the decomposition reaction system as an optimization goal based on finite-time thermodynamics is carried out. The reference reactor is heated counter-currently by high-temperature helium gas, the optimal reactor and the modified reactor are designed based on the reference reactor design parameters. With the EGRM as the optimization goal, the optimal control method is used to solve the optimal configuration of the reactor under the condition that both the reactant inlet state and hydrogen production rate are fixed, and the optimal value of total EGR in the reactor is reduced by 13.3% compared with the reference value. The reference reactor is improved on the basis of the total EGR in the optimal reactor, two modified reactors with increased length are designed under the condition of changing the helium inlet state. The total EGR of the two modified reactors are the same as that of the optimal reactor, which are realized by decreasing the helium inlet temperature and helium inlet flow rate, respectively. The results show that the EGR of heat transfer accounts for a large proportion, and the decrease of total EGR is mainly caused by reducing heat transfer irreversibility. The local total EGR of the optimal reactor distribution is more uniform, which approximately confirms the principle of equipartition of entropy production. The EGR distributions of the modified reactors are similar to that of the reference reactor, but the reactor length increases significantly, bringing a relatively large pressure drop. The research results have certain guiding significance to the optimum design of HI decomposition reactors.

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“…Substituting q = U(T He − T) into Equations (29) and continuing to omit other items irrelevant to T He yields:…”

Section: The Optimal Control Formulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Minimization of Entropy Generation Rate in Hydrogen Iodide Decomposition Reactor Heated by High-Temperature Helium

Kong

Chen

Xia

et al. 2021

Entropy

View full text Add to dashboard Cite

show abstract

“…Research aiming to optimize electronic device and heat sink designs to enhance their heat dissipation has attracted the interest of many scholars [ 1 , 2 ]. In recent years, extensive and in-depth investigations for heat transfer optimization in the light of constructal theory [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ] and entropy generation minimization [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ,…”

Section: Introductionmentioning

confidence: 99%

“…Bejan [ 25 , 26 ] first derived the corresponding entropy generation rate (EGR) formula for fluid flow with finite pressure difference and heat transfer with finite temperature difference, and proposed the principle of entropy generation minimization (EGM). Many scholars [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ] have performed extensive and in-depth researches on various processes [ 32 , 42 ], cycles [ 28 , 29 , 36 , 37 ], devices [ 30 , 31 , 35 , 40 ] and systems [ 44 , 45 , 46 ] based on EGM. Recently, various fluid flows such as Newtonian flow [ 93 ], carbon nanotube flow [ 94 ] and Darcy-Forchheimer nanofluid flow [ 95 ], microchannel heat sinks [ 96 ], heat exchangers [ 97 , 98 , 99 ], and so on, have been investigated with EGM.…”

Section: Introductionmentioning

confidence: 99%

“…The conventional metrics, such as the heat transfer enhancement and pressure drop, evaluate convective heat transfer from the view point of the first law of thermodynamics, while the entropy generation analysis is from the view point of the second law of thermodynamics by uniformly characterizing the irreversibility of heat transfer and fluid friction. The purpose of entropy generation minimization is to seek the minimization of thermodynamic irreversibility which is characterized and quantified by the indicators such as entropy generation rate, entropy generation number, Bejan number, and so on [ 44 , 45 , 46 ].…”

Section: Introductionmentioning

confidence: 99%

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Constructal Design of Elliptical Cylinders with Heat Generating for Entropy Generation Minimization

Wang

Xie

Yin

et al. 2020

Entropy

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A heat dissipation model of discrete elliptical cylinders with heat generation on a thermal conduction pedestal cooled by forced convection is established. Constructal design is conducted numerically by taking the distributions of thermal conductivity and heat generating intensity as design variables, the dimensionless entropy generation rate (DEGR) as performance indicator. The optimal designs for discrete elliptical cylinders with heat generating are obtained respectively, i.e., there are optimal distributions of heat generating intensity with its fixed total amount of heat sources, and there are optimal distributions of thermal conductivity with its fixed total amount of heat sources. These optimums for minimum DEGRs are different at different Reynolds numbers of airflow. The heat generating intensity can be decreased one by one appropriately in the fluid flow direction to achieve the best effect. When the Reynolds number of airflow is smaller, the thermal conductivity of heat source can be increased one by one appropriately in the fluid flow direction to achieve the best effect; when the Reynolds number of airflow is larger, the thermal conductivity of each heat source should be equalized to achieve the best effect. The results can give thermal design guidelines for the practical heat generating devices with different materials and heat generating intensities.

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Acknowledgments

Cited by 2 publications

References 0 publications

Minimization of Entropy Generation Rate in Hydrogen Iodide Decomposition Reactor Heated by High-Temperature Helium

Minimization of Entropy Generation Rate in Hydrogen Iodide Decomposition Reactor Heated by High-Temperature Helium

Constructal Design of Elliptical Cylinders with Heat Generating for Entropy Generation Minimization

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