Analysis of grid spacer effects on the flow and heat transfer of supercritical water flow in an inner sub-channel of a SCWR based on the second law of thermodynamics

Q, Qiu; Du, Xin; Zhao, Shuai; Zhu, Xun; Shen, Shengqiang

doi:10.1016/j.applthermaleng.2018.07.114

Cited by 9 publications

(3 citation statements)

References 30 publications

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“…Based on numerous research results of researchers, the SSG turbulence model best predicts the supercritical fluid flow heat transfer process. 17 , 24 The SSG Reynolds stress model is also known as the second-order pressure-strain model, and its specific expression is shown in formula 1 . In addition, the SSG turbulence model considers the effects of streamline curvature, vortex, and sudden changes in the strain rate in the flow process; it is suitable for flow field simulations with a high flow anisotropy.…”

Section: Numerical Approachmentioning

confidence: 99%

“…Although researchers have developed more than 10 turbulence models, in view of the dramatic physical changes of supercritical water at the quasi-critical point, none is universally applicable to accurately predict heat transfer in supercritical water. Based on numerous research results of researchers, the SSG turbulence model best predicts the supercritical fluid flow heat transfer process. , The SSG Reynolds stress model is also known as the second-order pressure-strain model, and its specific expression is shown in formula . In addition, the SSG turbulence model considers the effects of streamline curvature, vortex, and sudden changes in the strain rate in the flow process; it is suitable for flow field simulations with a high flow anisotropy. In formula , ϕ ij is the pressure-strain term, b ij is the Reynolds stress anisotropy tensor, defined as and S ij is the average strain rate, defined as Constant: C 1 = 3.4, C 1 * = 1.8, C 2 = 4.2, C 3 = 0.8, C 3 * = 1.3, C 4 = 1.25, C 4 = 0.4.…”

Section: Numerical Approachmentioning

confidence: 99%

“…However, experimental research is costly and time-consuming, and the influencing parameters in the experimental process are not unique. Therefore, numerical methods are widely used to study the flow and heat transfer characteristics of supercritical water with a single parameter. , Yang carried out a numerical calculation on the heat transfer of supercritical water flow in a 4 m long circular tube and compared the results with the experimental results to verify the accuracy of the numerical calculation. Shang used CFD software coupled with STAR-CD subroutine to conduct a numerical study on the flow and heat transfer characteristics of supercritical water in SCWR.…”

Section: Introductionmentioning

confidence: 99%

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Structural Effect of a Staggered-Blade-type Grid Spacer on the Flow and Heat Transfer Characteristics of Supercritical Water in a Triangular Core Channel

Wang

Zheng

et al. 2022

ACS Omega

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The flow and heat transfer characteristics of supercritical water within a triangular subchannel of a supercritical water-cooled reactor (SCWR) were numerically studied using the SSG turbulence model. The structural effect of staggered-blade-type grid spacers on the flow and heat transfer characteristics of supercritical water was analyzed. The results show that the wall temperatures calculated by the SSG model are consistent with the experimental data. The structure of the staggered-blade-type grid spacers has a significant effect on the supercritical heat transfer in the large specific heat region. The change in the inner-wall temperature and local heat transfer coefficient caused by the blocking rate at different leaf deflection angles has the same trend in the flow direction. The heat transfer coefficient peak gradually increases with an increase in deflection angle. A clear vortex is generated downstream of the grid spacer, and when the blade angle increases from 0 to 90°, the secondary flow is more obvious, and the velocity near the wall is the largest, which is about 1.99 times the center velocity. As the structure-blocking effect increases, the pressure drop in the subchannel gradually increases and the performance evaluation criteria first increase and then decrease. When using the staggered-blade-type grid spacer to improve the supercritical heat transfer effect, the spacing between adjacent grids should be ensured as far as possible, and avoid using it at the end of the channel.

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Section: Numerical Approachmentioning

confidence: 99%