This document summarizes research on the performance of a packed-bed thermal energy storage system using small-sized concrete material. The researchers tested different shapes of concrete material - spheres, cubes, and cylinders - in an experimental setup and analyzed temperature distribution, energy storage quantity, charging and discharging times, and pressure drop. Their results showed that cylinders provided better energy storage performance than spheres or cubes. Void fraction also affected energy storage quantity and pressure drop, with higher void fractions allowing more storage but also greater pressure drop. Faster flow rates led to shorter charging times but also faster discharging.

1. Performance Analysis of Packed- Bed Sensible Heat
Thermal Energy Storage with Small Sized Material
Paper By
Ganesh S. Warkhade, Santosh Mane
Presented By
Ganesh S. Warkhade
At
International Conference on Energy and Environment

2. Outline of Presentation
• Introduction
• Literature Review
• Testing Facility and Experimentation
• Results and Discussion
• Conclusion
• References

3. Introduction
TES Processes

4. Literature ReviewAuthor Materials Remark
Meier et al.
(1991)
Rock High temperature energy storage
Ammar et al.
(1992)
Spheres of
Egyptiain clay
Temperature distribution performance with different
time interval and energy stored in packed bed.
Gunerhan et al.
(2005)
Magmatic basalt
rock
Energy storage
Nsofor (2005) Zirconium oxide Advanced ceramic material that can withstand
corrosion and high temperatures
Dhifaoui et al.
(2007)
Glass Energy storage
Wongpanyo et al.
(2008)
Concrete Material composition for high temperature energy
storage
Lehmann et al.
(2008)
Concrete High temperature energy storage

5. Literature Review ContinuedSingh et al. (2008) Large size concrete
of 5 different shapes
Effect of void fraction, sphericity, energy stored,
correlations have been developed for Nusselt number
and friction factor as a function of Reynolds number
and void fraction.
Tyagi et al. (2011) Concrete Heat transfer and pressure drop, correlations have been
developed for Nusselt number and friction factor as a
function of Reynolds number and void fraction.
Hanchen et al.
(2011)
Rock High temperature energy storage
Prasad and
Muthukumar
(2013)
Concrete For pipe 6 fins are used and energy storage effect was
measured
Kuravi et al.
(2013)
Large size Ceramic
Brick
High temperature energy storage
Gil et al. (2014) NaCl Energy storage

6. Testing Facility and Experimentation
Schematic diagram of storage system.

7. Photograph of experimental setup

8. Material Concrete
The local materials volumetric ratios are
water (1): cement (1): sand (1.5): rock (1.5)
Density =2000 kg/m3
Thermal conductivity = 0.98 W/m/K
Specific heat = 820 J/kg/K
Photograph of material used
Sr.
No
Shape Dimension (m) Minimum volume
required (m3
)
Sphericity Void
fraction
Mass
(kg)
1 Sphere d = 0.038 0.00653 1 0.48 13.06
2 Cube s = 0.038 0.01054 0.806 0.32 21.04
3 Cylinder d = 0.0375,
h = 0.0375
0.01176 0.825 0.27 22.53
Thermo-physical properties of concrete and estimated mass of sensible heat storage material

9. Packing Arrangement of Packed Bed
(a) (b)
( c)
Photograph of material used with packing arrangement in packed bed for
(a) sphere, (b) cylinder, (c) cube.

10. Location of thermocouples in the packed bed
Parameters
•The air velocity was measured by a hot wire anemometer.
•Head loss in the bed (∆h) from U tube manometer.
•Air temperature at different locations.
•Surface temperature of material elements at different locations.

11. Results and Discussion
Temperature distribution performance on sphere
Charging of sphere
Average temperature at mass flow rate 0.021 kg/s.

12. Comparison of temperature at two different mass flow rates for sphere at height 500 mm.

13. Discharging of sphere
Average temperature at mass flow rate 0.021 kg/s

14. Comparison of temperature at two different mass flow rates for sphere

15. Performance of different shapes of packed bed material
Charging performance
Comparison of temperature at mass flow rate 0.021 kg/s for sphere ( = 0.48), cube ( = 0.32) ,ɛ ɛ
and cylinder ( =0.27)ɛ

16. Comparison of temperature at mass flow rate 0.0325 kg/s for sphere ( = 0.48), cube ( =ɛ ɛ
0.32) , and cylinder ( =0.27)ɛ

17. Discharging performance
Comparison of temperature at mass flow rate 0.021 kg/s for sphere ( = 0.48), cube ( =ɛ ɛ
0.32) , and cylinder ( =0.27)ɛ

18. Comparison of temperature at mass flow rate 0.0325 kg/s for sphere ( = 0.48), cube ( =ɛ ɛ
0.32) , and cylinder ( =0.27)ɛ

19. Effect of flow rate on charging time
Effect of flow rate on charging time

20. Effect of void fraction on quantity of energy storage
Rate of thermal energy in packed bed with void fraction for mass flow rate = 0.021 kg/s
sphere ( = 0.48), cube ( = 0.32) , and cylinder ( =0.27).ɛ ɛ ɛ

21. Rate of thermal energy in packed bed with void fraction for mass flow rate = 0.0325 kg/s
sphere ( = 0.48), cube ( = 0.32) , and cylinder ( =0.27)ɛ ɛ ɛ

22. Effect of pressure drop
Comparison of pressure drop with mass flow rates for sphere ( = 0.48), cube ( =ɛ ɛ
0.32) , and cylinder ( =0.27)ɛ

23. Conclusion
It is seen that the void fraction is more the charging process and discharging process is
quick, the void fraction is less the charging and discharging process is slow.
As the mass flow rate increases the charging time required for energy storage is less
and for discharging the energy discharging time is less.
The energy storage in packed bed is more for void fraction is less and energy storage is
less where void fraction more.
The pressure drop considers the void fraction is more then pressure drop is less and
void fraction is less the pressure drop is more.
Cylindrical shape is giving the better performance for energy storage as compared to
the sphere and cube.

24. References
[1] Dincer I., Rosen M.A., “Thermal energy storage, systems and applications”, New York: Wiley, (2002).
[2] Singh H., Saini R.P., Saini J.S., “A review on packed bed solar energy storage systems”, Int. J Renewable and Sustainable Energy
Reviews 14 (2010) 1059–1069 .
[3] Kuravi S., Trahan J., Goswami D.Y., Rahman M.M., Stefanakos E.K., “Review of thermal energy storage technologies and systems for
concentrating solar power plants”, Int. J Progress in Energy and Combustion Science 39 (2013) 285-319.
[4] Maithani R., Patil A.K., Saini J.S., “Investigation of effect of stratification on the thermal performance of packed bed solar air heater”, Int.
J Energy Science 3 (2013) 267-275.
[5] Singh R., Saini R.P., Saini J.S., “Models for predicting thermal performance of packed bed energy storage system for solar air heaters – a
Review”, The Open Fuels & Energy Science Journal,2 (2009) 47-53.
[6] Singh R., Saini R.P., Saini J.S., “Optimization of system parameters of packed bed solar energy storage system having storage material
elements of large size”, The Open Fuels & Energy Science Journal 2 (2009) 31-33.
[7] Singh R., Saini R.P., Saini J.S., “Simulated performance of packed bed solar energy storage system having storage material elements of
large size - Part I”, The Open Fuels & Energy Science Journal 1 (2008) 97-101.
[8] Singh R., Saini R.P., Saini J.S., “Simulated performance of packed bed solar energy storage system having storage material elements of
large size - Part II”, The Open Fuels & Energy Science Journal 1 (2008) 102-106.
[9] Singh R., Saini R.P., Saini J.S., “Simulated performance of packed bed solar energy storage system having storage material elements of
large size - Part III”, The Open Fuels & Energy Science Journal,1 (2008) 91-96.
[10] Tyagi K., Varun F., Singh S., Nautiyal H., “Experimental investigation of packed bed solar thermal energy system with cylindrical
elements”, Int. J Science and Technology 1(2011) 43-50.
[11] Allen K.G., Backstrom T.W., Kroger D.G., “Packed bed pressure drop dependence on particle shape, size distribution, packing
arrangement and roughness”, Int. J Powder Technology 246 (2013) 590–600.

25. Thank you