Solar thermal energy storage using latent heat : discharging energy from phase change material

Abstract

The amount of solar thermal energy on the earth is not constant; it depends on weather conditions and location. To resolve the mismatch between energy supply and energy demand in solar thermal systems, the useful solutions is to store this solar thermal energy using phase change materials (latent heat) named PCM. In this paper, we studied numerically the discharging and charged energy from and to PCM. To improve the conjugate heat transfer between the heat transfer fluid (water) and the PCM at liquid state, we simulate the influence of the addition of fins to our storage unit with various configurations including online and staggered fins. Then we studied the effect of the inlet fluid flow and the fluid inlet temperature on the total PCM freezing time and the effect of the natural convection in our storage unit. Furthermore, we valid an experimental work.

In addition, we used the computational fluid dynamic ansysFluent 15 based on enthalpy formulation to solve the formulation, where we develop three users define to describe the viscosity, density and the thermal conductivity of the PCM.  

Keywords

• PCM,solar thermal energy,freezing time,AnsysFluent,fins

References

1. [1] M.K. Anuar Sharif, A.A. Al-Abidi, S. Mat, K. Sopian, M.H. Ruslan, M.Y. Sulaiman and M.A.M Rosli, “Review of the application of phase change material for heating and domestic hot water systems ”, Renewable and Sustainable Energy Reviews. 42, 557–568 (2015).
2. [2] Jundika C. Kurnia, Agus P. Sasmito, Sachin V. Jangam and Arun S. Mujumdar, “Improved design for heat transfer performance of a novel phase change material (PCM) thermal energy storage (TES) ”, Applied Thermal Engineering, 50, 896-907(2013).
3. [3] DN Nkwetta, P-E Vouillamoz, F Haghighat, M El-Mankibi, A Moreauand A. Daoud, “ Impact of phase change materials types and positioning on hot water tank thermal performance: using measured water demand profile ” , Appl Thermal Eng,1.2(67),460–468 ( 2014).
4. [4] S Aliyadeh,“An experimental and numerical study of thermal stratification in a horizontal solar storage tank ” , Solar Energy, 66 (6), 409–421 (1999).
5. [5] J E B Nelson, A R Balakrishnan and S S Murthy,“ Parametric studies on thermally stratified chilled water storage systems” , Applied Thermal Eng,19, 89–115 (1999 ).
6. [6] J E B Nelson, A R Balakrishnan and S S Murthy,“Experiments on stratified chilled-water tanks”, Int J Refrigeration,22, 216( 1999).
7. [7] I Al-Hinti, A Al-Ghandoor, A Maaly, I Abu Naqeera, Z Al-Khateeb and O Al-Sheikh, “ Experimental investigation on the use of water-phase change material storage in conventional solar water heating systems” , Energy Convers Manage, 51, 1735–1740 (2010).
8. [8] M Mazman, LF Cabeza, H Mehling, M Nogues, H Evliya and HÖ. Paksoy,“ Utilization of phase change materials in solar domestic hot water systems”, Renewable Energy, 34, 1639–1643 ( 2009).

9. [9] A Barba and M Spiga“ Discharge mode for encapsulated PCMs in storage tanks”, Solar Energy, 74, 141–148 (2003).
10. [10] A López-Navarro, J Biosca-Taronger, JM Corberán, C Peñalosa, A Lázaro, P Dolado, et al. , “ Performance characterization of a PCM storage tank “ Appl Energy,119 ,151–162 (2014).
11. [11] F Aghbalou, F Badia and J Illa “ Exergetic optimization of the solar collector and thermal energy storage system ”, Int J Heat Mass Transfer,49, 1255–1263 (2006).
12. [12] R Padovan and M. Manzan“ Genetic optimization of a PCM enhanced storage tank for solar domestic hot water systems”, Solar Energy, 103, 563–753(2014).
13. [13] RE Murray and D Groulx“, Experimental study of the phase change and energy characteristics inside a cylindrical latent heat energy storage system: Part 1: Consecutive charging and discharging”, Renewable Energy, 62, 571–581 (2014).
14. [14] A A Al-Abidi, Sohif Mat, K Sopian, MY Sulaiman and Abdulrahman Th Mohammad, “ Numerical study of PCM solidification in a triplex tube heat exchanger with internal and external fins,” International Journal of Heat and Mass Transfer, 61, 684–695 ( 2013).
15. [15] E M.Sparrow, E D Larson, and J W Ramsey, “ freezing on a finned tube for either conduction- controlled or natural-convection-controlled heat transfer ”, Int. J. Heat Mass Transfer,24,213- 284,
16. [16] Maryam Gharebaghi and I Sezai, “Enhancement of Heat Transfer in Latent Heat Storage Modules with Internal Fins”, Numerical Heat Transfer, A (53), 749–765 (2008).
17. [17] Marcel Lacroix, “Study of the heat transfer behavior of a latent heat thermal energy storage unit with a finned tube”, Int .J. Heat Mass Transfer, 36 (8), 2083-2092 (1993).
18. [18] R Velraj, R V Seeniraj, B Hafner, C Faber and K. Schwarzer, “ experimental analysis and numerical modeling of inward solidification on a finned vertical tube for a latent heat storage unit ”, Solar Energy,60(5),281-290 (1997).
19. [19] K A R Ismail, C L F Alves and M S Modesto, “Numerical and experimental study on the solidification of PCM around a vertical axially inned isothermal cylinder”, Applied Thermal Engineering, 21, 53-77(2001).