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An Integrated Thermal and Mechanical Performance Analysis of Effect of Cold Molten Salt Temperature for Thermocline Tank

  • Gang WangEmail author
  • Shuyang Yu
  • Shuqun Niu
  • Zeshao Chen
  • Peng Hu
Article
  • 8 Downloads

Abstract

To study the effect law of cold molten salt temperature on both the thermal energy storage and mechanical performances of a thermocline molten salt tank, a numerical model of the tank which includes a multi-layer wall is established. The tank wall consists of three layers, which are firebrick, steel, and ceramic, respectively. Fluent code is employed to carry out the simulations of five different complete operation cycles of the thermocline tank. An integrated thermal and mechanical performance analysis of the effect of cold molten salt temperature for the thermocline tank is carried out. The analysis results reveal that for all the simulated cases, the thermocline is steady, and both the charging and discharging processes of the tank are stable. The thermocline thickness of the charging process can be smaller than that of the discharging one. The axial temperature of steel wall does not change synchronously with the central axial temperature of molten salt during both charging and discharging processes. As the cold molten salt temperature decreases, the thermocline thickness as well as the maximum mechanical stress of the steel wall increases. Hence, it can be drawn that increasing the cold molten salt temperature properly will be of benefit to both the energy storage performance and stability of the thermocline tank structure.

Keywords

CSP Effect of cold molten salt temperature Energy storage Thermocline tank Integrated thermal and mechanical analysis 

Abbreviations

Cp

Specific heat, J·kg−1K−1

D

Tank diameter, m

D

Inner diameter of the inlet and outlet pipeline, m

E

Elasticity modulus, Pa

F

Inertial coefficient of the porous medium

H

Height of the filling area, m

H

Height of the upper and lower distributor zones, m

hi

Interstitial heat transfer coefficient, W·m−2K−1

K

Intrinsic permeability of the porous medium, m2

\( k \)

Thermal conductivity, W·m−1K−1

L

Thickness, m

T

Temperature, K

u

Velocity, m·s−1

Greek symbols

α

Thermal expansion coefficient, K−1

εm

Mechanical strain

εt

Thermal strain

δ

Thermocline thickness, m

Θ

Dimensionless temperature

μ

Viscosity, kg·m−1s−1

ρ

Density, kg·m−3

\( \upsigma \)

Principal stress, Pa

σmax

Maximum mechanical stress, Pa

σγ

Yield strength, Pa

Subscripts

b

Bottom

c

Cold molten salt

h

Hot molten salt

in

Inlet

l

Liquid molten salt

m

Mechanical

max

Maximum

min

Minimum

s

Solid filler

t

Thermal

top

Top

Notes

Acknowledgments

The authors appreciate the support of the Excellent Youth Foundation of Jilin Province of China (Grant No. 20190103062JH).

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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Gang Wang
    • 1
    Email author
  • Shuyang Yu
    • 1
  • Shuqun Niu
    • 1
  • Zeshao Chen
    • 2
  • Peng Hu
    • 2
  1. 1.School of Energy and Power EngineeringNortheast Electric Power UniversityJilin CityChina
  2. 2.School of Engineering ScienceUniversity of Science and Technology of ChinaHefeiChina

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