An in-depth numerical investigation of a solar latent heat storage unit incorporating phase change materials

Year 2025, Volume: 11 Issue: 4, 1231 - 1244, 31.07.2025

Mustapha Faraji , Kenza Oudaoui

Abstract

The energy storage method is very important for many engineering domains, providing multi-ple benefits for a variety of fields. The requirement for an effective way to store heat generated during times of high solar radiation and, recover it later when there is no sun is one of the most frequent issues that solar power systems encounter. Therefore, storing energy using phase change materials (PCM) is an important solution for overcoming the mismatch between the energy supply and demand in solar thermal systems. We study a new heat storage system based on 3 different phase change materials and not on a single one. Most of the previous studies focus on charging or storing heat in a PCM. But crucial problems arise during discharge. Given the low thermal conductivity of the phase change materials, are we able to recover all the energy we have stored and how? This is the major objective of this study. The novel heat storage unit uses three different phase change materials instead of one. These phase change materials are located at variable positions to optimize the performance of the latent heat storage unit. The main pur-pose of the present paper is to numerically study the discharge process of multiple phase change materials in a coaxial solar water/PCM heat exchanger. Different configurations, including the phase change material position and PCM thickness are analyzed. These materials were selected according to their thermophysical properties (melting temperature, thermal conductivity and la-tent heat of fusion). For this purpose, a cylindrical two-dimensional mathematical model based on energy conservation equations was developed. The governing equations were discretized over finite volume controls using the enthalpy method and several numerical simulations were conducted to study multiple PCM/water heat exchangers behaviour. The impacts of the phase change material position and radius are experienced to evaluate the thermal performance of the heat exchanger. The optimal configuration for solidification is determined. It was found that, the heating time can be extended by properly moving the various phase change materials within the tube. Numerous cases are examined. The two cases that offer both advantageous heating choices have a heat delivery time to water that exceeds 138 minutes. When the impact of tube radius is examined, it is discovered that, in the case of a very thin PCM layer, the water records a high tem-perature of 60°C for 40 minutes before declining somewhat but staying above 42°C until t=56 minutes. For about 53 minutes, the water outlet temperature stays above 40°C when the phase change materials cylinder thickness reaches 17 mm. During the heat discharge, a comparatively improved heat evacuation capability is noted. Nevertheless, 28 kJ of heat are not utilized in total. The heat exchanger is unable to release the remaining energy.

Keywords

Heat Discharge , HeatExchangers , Heat Transfer , Latent Heat Storage , Phase , Change Materials Solidification , Process , Solar Energy Water , Heating

References

• 1. Al Shawa B. An equitable energy allowance for all: Pathways for a below 2 °C-compliant global buildings sector. Energy Rep 2022;8:15377–15398. [CrossRef]
• 2. Dey B, Misra S, Garcia Marquez FP. Microgrid system energy management with demand response program for clean and economical operation. Appl Energy 2023;334:120717. [CrossRef]
• 3. Nassar NT, Wilburn DR, Goonan TG. Byproduct metal requirements for U.S. wind and solar photovoltaic electricity generation up to the year 2040 under various Clean Power Plan scenarios. Appl Energy 2016;183:1209–1226. [CrossRef]
• 4. Ribezzo A, Falciani G, Bergamasco L, Fasano M, Chiavazzo E. An overview on the use of additives and preparation procedure in phase change materials for thermal energy storage with a focus on long term applications. J Energy Storage 2022;53:105140. [CrossRef]
• 5. Anilkumar BC, Maniyeri R, Anish S. Optimum selection of phase change material for solar box cooker integrated with thermal energy storage unit using multi-criteria decision-making technique. J Energy Storage 2021;40:102807. [CrossRef]
• 6. Ghosh D, Ghose J, Datta P, Kumari P, Paul S. Strategies for phase change material application in latent heat thermal energy storage enhancement: Status and prospect. J Energy Storage 2022;53:105179. [CrossRef]
• 7. Al-Zurfi HA, Talib MA, Hassan QH, Aljabri GJ. A numerical study to improve the efficiency of solar collector used for water heating using phase change material. J Adv Res Numer Heat Transf 2024;17:1–13. [CrossRef]
• 8. Seeniraj RV, Velraj R, Narasimhan NL. Thermal analysis of a finned-tube LHTS module for a solar dynamic power system. Heat Mass Transf 2002;38:409–417. [CrossRef]
• 9. Akgün M, Aydın O, Kaygusuz K. Experimental study on melting/solidification characteristics of a paraffin as PCM. Energy Convers Manag 2007;48:669–678. [CrossRef]
• 10. Talebizadeh Sardari P, Mahdi JM, Mohammed HI, Moghimi MA, Eisapour AH, Ghalambaz M. Consecutive charging and discharging of a PCM-based plate heat exchanger with zigzag configuration. Appl Therm Eng 2021;193:116970. [CrossRef]
• 11. Wang P, Li D, Huang Y, Zheng X, Wang Y, Peng Z, et al. Numerical study of solidification in a plate heat exchange device with a zigzag configuration containing multiple phase-change-materials. Energies 2016;9:394. [CrossRef]
• 12. Agyenim F, Eames PC, Smyth M. A comparison of heat transfer enhancement in a medium temperature thermal energy storage heat exchanger using fins. Sol Energy 2009;83:1509–1520. [CrossRef]
• 13. Al-Abidi AA, Mat S, Sopian K, Sulaiman MY, Mohammad AT. Numerical study of PCM solidification in a triplex tube heat exchanger with internal and external fins. Int J Heat Mass Transf 2013;61:684–695. [CrossRef]
• 14. El-Dessouky H, Al-Juwayhel F. Effectiveness of a thermal energy storage system using phase-change materials. Energy Convers Manag 1997;38:601–617. [CrossRef]
• 15. Wu Y, Li D, Jiang W, Zhu S, Zhao X, Arıcı M, et al. Energy storage and exergy efficiency analysis of a shell and tube latent thermal energy storage unit with non-uniform length and distributed fins. Sustain Energy Technol Assess 2022;53:102362. [CrossRef]
• 16. Nguyen Trung K. The temperature distribution of the wet cylinder liner of V-12 engine according to calculation and experiment. J Therm Eng 2021;7:1872–1884. [CrossRef]
• 17. Akula R, Balaji C. Thermal management of 18650 Li-ion battery using novel fins–PCM–EG composite heat sinks. Appl Energy 2022;316:119048. [CrossRef]
• 18. Pulagam MK, Rout SK, Sarangi SK. A state-of-the-art review on thermo fluid performance of brazed plate heat exchanger for HVAC application. J Therm Eng 2024;10:1390–1410. [CrossRef]
• 19. Gürtürk M, Kok B. A new approach in the design of heat transfer fin for melting and solidification of PCM. Int J Heat Mass Transf 2020;153:119671. [CrossRef]
• 20. Benbrika M, Teggar M, Benbelhout M, Ismail KAR, Bouabdallah S. Effect of orientation of elliptic tube on the total melting time of latent thermal energy storage systems. J Therm Eng 2021;7:1479–1488. [CrossRef]
• 21. Rahimi M, Ranjbar AA, Ganji DD, Sedighi K, Hosseini MJ, Bahrampoury R. Analysis of geometrical and operational parameters of PCM in a fin and tube heat exchanger. Int Commun Heat Mass Transf 2014;53:109–115. [CrossRef]
• 22. Bouzennada T, Mechighel F, Ismail T, Kolsi L, Ghachem K. Heat transfer and fluid flow in a PCM-filled enclosure: Effect of inclination angle and mid-separation fin. Int Commun Heat Mass Transf 2021;124:105280. [CrossRef]
• 23. Pulagam MKR, Rout SK, Muduli KK, Syed SA, Barik D, Hussein AK. Internal finned heat exchangers: Thermal and hydraulic performance review. Int J Heat Technol 2024;42:583–592. [CrossRef]
• 24. Pelella F, Zsembinszki G, Viscito L, Mauro AW, Cabeza LF. Thermo-economic optimization of a multi-source (air/sun/ground) residential heat pump with a water/PCM thermal storage. Appl Energy 2023;331:120398. [CrossRef]
• 25. Voller VR, Prakash C. A fixed grid numerical modelling methodology for convection-diffusion mushy region phase-change problems. Int J Heat Mass Transf 1987;30:1709–1719. [CrossRef]
• 26. Farid MM, Kanzawa A. Thermal performance of a heat storage module using PCM’s with different melting temperatures: Mathematical modeling. J Sol Energy Eng 1989;111:152–157. [CrossRef]
• 27. Patankar S. Numerical heat transfer and fluid flow. 1st ed. Boca Raton: CRC Press; 1980.
• 28. Lacroix M. Numerical simulation of a shell-and-tube latent heat thermal energy storage unit. Sol Energy 1993;50:357–367. [CrossRef]
• 29. Kenisarin M, Mahkamov K. Solar energy storage using phase change materials. Renew Sustain Energy Rev 2007;11:1913–1965. [CrossRef]
• 30. Farid MM, Khudhair AM, Razack SAK, Al-Hallaj S. A review on phase change energy storage: Materials and applications. Energy Convers Manag 2004;45:1597–1615. [CrossRef]