Experimental study on heat transfer of supercritical Freon flowing upward in a circular tube

Zhang, Siyu; Gu, Hanyang; Xu, Cheng; Xiong, Zhenqin

doi:10.1016/j.nucengdes.2014.09.017

Cited by 50 publications

(20 citation statements)

References 14 publications

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“…In general, the effects of system parameters on the heat transfer to supercritical water in the rod bundle with wire wraps are similar to those observed in bare bundle or annular channel [9,24,25].…”

Section: Parameter Effectssupporting

confidence: 63%

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Experimental study on heat transfer to supercritical water in 2×2 rod bundle with wire wraps

et al. 2016

Experimental Thermal and Fluid Science

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Section: Parameter Effectssupporting

confidence: 63%

“…Uncertainty of Nusselt number is analyzed based on the method reported in Ref. [25]. 80.3% of the Nu deducted by experimental data fall into the error range smaller than 5.0%, and 97.2% fall into the error range smaller than 10%.…”

Section: Data Reductionmentioning

confidence: 99%

Experimental study on heat transfer to supercritical water in 2×2 rod bundle with wire wraps

et al. 2016

Experimental Thermal and Fluid Science

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“…Zahlan's method and Cheng's method had quite large positive deviations with a good deal of scatter. For the R134a‐to‐CO 2 scaling (Figure B,D,F), all the 3 scaling methods give negative deviation for the Feuerstein R134a data, while relatively uniform deviation distribution for the Zhang R134a data . The present method gave an average deviation of −27% with a lowest standard deviation of 24% among the 3 methods.…”

Section: New Dimensionless Number and Scaling Lawsmentioning

confidence: 79%

Fluid-to-fluid scaling of heat transfer to mixed convection flow of supercritical pressure fluids

et al. 2018

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Summary Fluid‐to‐fluid scaling for supercritical heat transfer can effectively reduce the difficulty and cost of heat transfer experiments in supercritical boilers and supercritical water reactors and can reduce the number of experiments by converting experimental data of the model fluid to the prototype fluid in organic Rankine cycles. Currently, most existing scaling methods are only suitable for forced convection, while few are developed for mixed convection where buoyancy significantly affects the heat transfer. This paper attempts to extend the applicability of scaling method to mixed convection with the aid of computational fluid dynamic simulations. The scaling parameters were analyzed first and then the shear‐stress transport k‐ω model was used to analyze the supercritical heat transfer characteristics of water and R134a to provide further information for developing a dimensionless number. The results show that significant variations of properties and flow parameters occur in the layer of y+ = 5 to 100 and the axial velocity gradient in this layer changes in quite a similar manner to the wall temperature. Based on numerical results, the axial velocity gradient was used with a thermal resistance analogy to derive a new dimensionless number, Re−0.9πA, to scale the mass flux. Then, a set of fluid‐to‐fluid scaling laws were developed to predict the heat transfer to supercritical fluids. To validate the newly proposed scaling laws, well‐developed correlations were used for forced convection flow and a direct validation method was developed for buoyancy‐influenced flow. Results show that this new scaling method exhibits reasonable accuracy for both forced and mixed convection heat transfer with supercritical fluids.

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“…Yamashita et al [5] commented that the Watts and Chou [18] correlation developed from water gives the best agreement against the experimental data for R-22. Zhang et al [16] suggested that the correlation proposed by Jackson [19] shows the best agreement against the experimental data for R-134a. He et al [17] recommended two correlations that were originally developed from water proposed by Yamagata et al [8] and Jackson [19] upon the R-245fa experimental data.…”

Section: Introductionmentioning

confidence: 97%

“…However, there is few research concerning the heat transfer performance of organic fluids. The investigation for organic fluids in smooth tubes are listed on Table 1 [5,[14][15][16][17]. Most investigations applied the correlations that were developed from water or carbon dioxide to predict the performance of organic fluids.…”

Section: Introductionmentioning

confidence: 99%

A Criterion of Heat Transfer Deterioration for Supercritical Organic Fluids Flowing Upward and Its Heat Transfer Correlation

Liaw

Wang

2020

Energies

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The main objective of this study was to develop the supercritical heat transfer correlation applicable for organic fluids when flowing upward in smooth tubes based on the available experimental data. The organic fluids contain R-22, R-134a, R-245fa and Ethanol and the associated heat transfer characteristics were compared with non-organic fluids like water and carbon-dioxide (CO2). It was found that the limit heat flux may result in heat transfer deterioration (HTD) of organic fluid and the corresponding values are much smaller than water or CO2. A new criterion to predict the HTD was developed and this criterion yields the best predictive ability against database. It was found that HTD occurs can be well described by the acceleration parameter evaluated at the wall condition rather than at bulk condition. For estimation of the supercritical heat transfer coefficient (HTC) for organic fluid, the present study proposes a new correlation with a physically based correction factor, which gives satisfactory predictions against the HTC of supercritical organic fluid. The new correlation can offer the smallest average deviation of 0.007 and standard deviation of 0.181 among the existing correlations.

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Experimental study on heat transfer of supercritical Freon flowing upward in a circular tube

Cited by 50 publications

References 14 publications

Experimental study on heat transfer to supercritical water in 2×2 rod bundle with wire wraps

Experimental study on heat transfer to supercritical water in 2×2 rod bundle with wire wraps

Fluid-to-fluid scaling of heat transfer to mixed convection flow of supercritical pressure fluids

A Criterion of Heat Transfer Deterioration for Supercritical Organic Fluids Flowing Upward and Its Heat Transfer Correlation

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