Thermal Stratification in Solar Water Storage Tanks through Inlet Port Diffuser Optimization during Charge and Discharge Processes

Abstract:

The enhancement of thermal stratification in solar storage tanks is a crucial aspect of advancing solar energy technology. This study presents an experimental investigation conducted on a vertical cylindrical hot solar water storage tank operating in a dynamic mode, involving simultaneous charging and discharging. The experiment aims to assess the impact of varying inlet water flow rates (4, 6, 8, 10 L/min) on thermal stratification within the tank and explores strategies to mitigate heat losses to the environment and minimize mixing effects caused by the inlet fluid flow. The experimental setup incorporates insulation and an inlet port diffuser section to optimize the distribution of inlet water during the charging and discharging states. The results reveal that the utilization of an inlet port diffuser significantly improves thermal stratification by reducing heat losses and minimizing mixing effects, as evidenced by improved Richardson numbers. Additionally, this study contributes to the development of a compact solar domestic hot water (SDHW) solution.

• Periodical: Engineering Headway (Volume 8)
• Pages: 39-53
• DOI: https://doi.org/10.4028/p-1r0MVz
• Online since: June 2024
• Authors: Elaf Sadeq Barrak*, Karrar A. Hammodi, Ahmed Mouthanna
• Keywords: Charge, Discharge State, Flow Rate, Storage Tank, Thermal Stratification

References

[1] T. Li, Y. Liu, D. Wang, K. Shang, and J. Liu, "Optimization Analysis on Storage Tank Volume in Solar Heating System," in Procedia Engineering, Elsevier Ltd, 2015, p.1356–1364.

DOI: 10.1016/j.proeng.2015.09.019

[2] S. A. Zavattoni, M. C. Barbato, A. Pedretti, and G. Zanganeh, "Single-tank TES System - Transient Evaluation of Thermal Stratification According to the Second-law of Thermodynamics," in Energy Procedia, Elsevier Ltd, May 2015, p.1068–1077.

DOI: 10.1016/j.egypro.2015.03.213

[3] S. M. Flueckiger, Z. Yang, and S. V. Garimella, "Review of molten-salt thermocline tank modeling for solar thermal energy storage," Heat Transfer Engineering, vol. 34, no. 10. p.787–800, Aug. 09, 2013.

DOI: 10.1080/01457632.2012.746152

[4] S. Li, Y. Zhang, K. Zhang, X. Li, Y. Li, and X. Zhang, "Study on performance of storage tanks in solar water heater system in charge and discharge progress," in Energy Procedia, Elsevier Ltd, 2014, p.384–393.

DOI: 10.1016/j.egypro.2014.02.045

[5] I. Ortega-Fernández, S. A. Zavattoni, J. Rodríguez-Aseguinolaza, B. D'Aguanno, and M. C. Barbato, "Analysis of an integrated packed bed thermal energy storage system for heat recovery in compressed air energy storage technology," Appl Energy, vol. 205, p.280–293, 2017.

DOI: 10.1016/j.apenergy.2017.07.039

[6] P. Gajbhiye, N. Salunkhe, S. Kedare, and M. Bose, "Experimental investigation of single media thermocline storage with eccentrically mounted vertical porous flow distributor," Solar Energy, vol. 162, p.28–35, Mar. 2018.

DOI: 10.1016/j.solener.2017.12.062

[7] M. Farmahini-Farahani, "Investigation of four geometrical parameters on thermal stratification of cold water tanks by exergy analysis," 2012.

DOI: 10.1504/ijex.2012.046814

[8] Ł. Grabowski, P. Karpiński, and P. Magryta, "Simulation Research of the Influence of Compression Ratio on the Performance of an Aircraft Piston Diesel Engine," Advances in Science and Technology Research Journal, vol. 14, no. 3, p.175–181, Sep. 2020.

DOI: 10.12913/22998624/122195

[9] O. Abdelhak, H. Mhiri, and P. Bournot, "CFD analysis of thermal stratification in domestic hot water storage tank during dynamic mode," Build Simul, vol. 8, no. 4, p.421–429, Aug. 2015.

DOI: 10.1007/s12273-015-0216-9

[10] A. Jabbar, N. Khalifa, A. T. Mustafa, and F. A. Khammas, "Experimental Study Of Temperature Stratification In A Thermal Storage Tank In The Static Mode For Different Aspect Ratios," vol. 6, no. 2, 2011, [Online]. Available: www.arpnjournals.com

[11] A. J. Ghajar and Y. H. Zurigat, "Numerical study of the effect of inlet geometry on stratification in thermal energy storage," Numeri Heat Transf A Appl, vol. 19, no. 1, p.65–83, 1991.

DOI: 10.1080/10407789108944838

[12] M. Y. Haller, W. Streicher, E. Andersen, and S. Furbo, "COMPARARATIVE ANALYSIS OF THERMAL ENERGY STORAGE STRATIFICATION EFFICIENCY-A NEW METHOD COMBINES ADVANTAGES OF PREVIOUS APPROACHES."

[13] M. Jannatabadi, "An experimental study of hot water consumption on the thermal performance of a horizontal mantle tank," World Appl Sci J, vol. 19, no. 9, p.1322–1326, 2012.

[14] Z. Wang, H. Zhang, H. Huang, B. Dou, X. Huang, and M. A. Goula, "The experimental investigation of the thermal stratification in a solar hot water tank," Renew Energy, vol. 134, p.862–874, Apr. 2019.

DOI: 10.1016/j.renene.2018.11.088

[15] J. Fan and S. Furbo, "THERMAL STRATIFICATION IN A HOT WATER TANK ESTABLISHED BY HEAT LOSS FROM THE TANK."

DOI: 10.1016/j.solener.2012.07.026

[16] N. Altuntop, V. Ozceyhan, Y. Tekin, and S. Gunes, "HT2008-56040 THE EFFECT OF OBSTACLE GEOMETRY AND POSITION ON THERMAL STRATIFICATION IN SOLAR HOT WATER STORAGE TANKS," 2008. [Online]. Available: http://www.asme.org/about-asme/terms-of-use

DOI: 10.1115/ht2008-56040

[17] P. Jenyongsak and P. Trinuruk, "Investigation of thermal stratification in a thermal storage tank with a curve edge obstacle plate," IOP Conf Ser Mater Sci Eng, vol. 1137, no. 1, p.012076, May 2021.

DOI: 10.1088/1757-899x/1137/1/012076

[18] W. Lou, A. Arrivé, B. Xie, J. Aubril, Y. Fan, and L. Luo, "Optimized flow distributor for stabilized thermal stratification in a single-medium thermocline storage tank: A numerical and experimental study," vol. 263, 2023.

DOI: 10.1016/j.energy.2022.125709

[19] E. S. Brak AsstProfDr Abdul Salam DM, "Study the Effect of Heat Losses on the Thermal Stratification in Cylindrical Hot Water Storage Tank," 2018.

[20] M. Alkhalaf, A. Ilinca, and M. Y. Hayyani, "CFD Investigation of Ventilation Strategies to Remove Contaminants from a Hospital Room," Designs (Basel), vol. 7, no. 1, Feb. 2023.

DOI: 10.3390/designs7010005

[21] S. Knudsen and S. Furbo, "Thermal Stratification in Vertical Mantle Tanks."

[22] S. A. Jazayeri, E. Molla, and H. Khoei, "Numerical Comparison of Thermal Stratification due Natural Convection in Densified LO X and LN 2 Tanks," Am J Appl Sci, vol. 5, no. 12, p.1773–1779, 2008.

DOI: 10.3844/ajassp.2008.1773.1779

[23] L. F. Cabeza, "Advances in thermal energy storage systems: Methods and applications," in Advances in Thermal Energy Storage Systems: Methods and Applications, Elsevier, 2020, p.37–54.

DOI: 10.1016/B978-0-12-819885-8.00002-4

[24] Z. Lavan and J. Thompson, "Experimental Study of Thermally Stratified Hot Water Storage Tanks."

[25] J.A. Duffie and W.A. Beckman, Solar engineering of thermal processes. Wiley, 2013.

[26] E.M. Kleinbach, "Performance Study of One-Dimensional Models for Stratified Thermal Storage Tank," 1990.

[27] C. A. Cruickshank, "EVALUATION OF A STRATIFIED MULTI-TANK THERMAL STORAGE FOR SOLAR HEATING APPLICATIONS," 2009.

[28] Z. Yang and S. V. Garimella, "Thermal analysis of solar thermal energy storage in a molten-salt thermocline," Solar Energy, vol. 84, no. 6, p.974–985, Jun. 2010.

DOI: 10.1016/j.solener.2010.03.007

[29] V. Tambrallimath and A. Patil, "Thermal Stratification in Vertical Solar Water Heater Tank," 2014. [Online]. Available: www.ijiset.com

[30] L. Kong, W. Yuan, and N. Zhu, "CFD Simulations of Thermal Stratification Heat Storage Water Tank with an Inside Cylinder with Openings," in Procedia Engineering, Elsevier Ltd, 2016, p.394–399.

DOI: 10.1016/j.proeng.2016.06.419

[31] H. Peng and S. Mohammadinia, "Modeling and simulation of ventilation and cooling of aircraft piston engine based on genetic algorithm," Engineering Applications of Computational Fluid Mechanics, vol. 14, no. 1, p.980–988, Jan. 2020.

DOI: 10.1080/19942060.2020.1784797

[32] S. Göppert, R. Lohse, T. Urbaneck, U. Schirmer, B. Platzer, and P. Steinert, "Computations Of The Fluid Flow In Stratification Pipes For Solar Storage Tanks."

DOI: 10.1016/j.solener.2009.05.007

[33] E. Sadeq Barrak, "Comparison and validation of turbulence models in the numerical study of heat exchangers."

[34] Y.H. Zurigat, P.R. Liche, and A.J. Ghajar, "Influence of inlet geometry on mixing in termocline thermal energy storage."

[35] Z. Wang, H. Zhang, B. Dou, G. Zhang, and W. Wu, "Influence of inlet structure on thermal stratification in a heat storage tank with PCMs: CFD and experimental study," Appl Therm Eng, vol. 162, Nov. 2019.

DOI: 10.1016/j.applthermaleng.2019.114151

[36] B. Xie, N. Baudin, J. Soto, Y. Fan, and L. Luo, "Experimental and numerical study on the thermocline behavior of packed-bed storage tank with sensible fillers."

DOI: 10.1016/j.renene.2023.03.107

[37] L. Gao, H. Lu, B. Sun, D. Che, and L. Dong, "Numerical and experimental investigation on thermal stratification characteristics affected by the baffle plate in thermal storage tank," J Energy Storage, vol. 34, Feb. 2021.

DOI: 10.1016/j.est.2020.102117

[38] H.A. Saheb, A.A. Mahdi, and Q.R. Al-amir, "A Comparative Study of Performance Between Two Combined Ventilation Systems and Their Effect On Indoor Air Quality and Thermal Comfort Inside Office Rooms," IOP Conf Ser Mater Sci Eng, vol. 1095, no. 1, p.012001, Feb. 2021.

DOI: 10.1088/1757-899x/1095/1/012001