STRUCTURAL OPTIMIZATION AND PERFORMANCE ANALYSIS OF U-TUBULAR PHASE CHANGE HEAT STORAGE EVACUATED SOLAR COLLECTOR TUBE

Liu Xianping; Wang Ye; Lei Yuhao; Yan Daren; Han Qiaoyun

doi:10.19912/j.0254-0096.tynxb.2023-1647

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Acta Energiae Solaris Sinica ›› 2024, Vol. 45 ›› Issue (9) : 451-457. DOI: 10.19912/j.0254-0096.tynxb.2023-1647

STRUCTURAL OPTIMIZATION AND PERFORMANCE ANALYSIS OF U-TUBULAR PHASE CHANGE HEAT STORAGE EVACUATED SOLAR COLLECTOR TUBE

Liu Xianping¹, Wang Ye¹, Lei Yuhao¹, Yan Daren², Han Qiaoyun¹

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Abstract

To enhance the thermal performance of phase change heat storage evacuated solar collectors, a new type of U-tubular phase change heat storage evacuated solar collector tube structure with an integrated axial double-wing fin structure is proposed. This design aims to address the issues of low heat transfer performance and low heat release efficiency of the collector tube when the phase change filling material is in a solid state. The influence of the main structural parameters of the fin on the heat release and heat storage performance of the collector tube is analyzed under different mass flow operating conditions, and the optimal fin structure parameters are determined. Furthermore, the performance of collector tubes with two conventional structures is compared and analyzed. The results indicate that, for the all-glass evacuated solar collector tube with an outer diameter of 58 mm, using a composite phase change filling material consisting of Na₂SO₄·10H₂O and graphite （mass ratio 92%：8%）, the optimal finned structure parameters, fin length/fin angle, for achieving the best heat release and heat storage performance are determined to be 17 mm/60°. The optimal fin structure significantly improves the heat transfer performance within the collector tube and enhances the temperature uniformity of the phase change filling material. Comparing the collector tube with the round fin and no fin structure, the optimal fin structure in the new U-tubular phase change heat storage evacuated solar collector tube increases the heat release by up to 6.4% and 112.6% and improves the heat release efficiency by up to 6.4% and 117.4%, respectively.

Key words

phase change / heat storage / evacuated solar collector / evacuated solar collector tube / heat release properties

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Liu Xianping, Wang Ye, Lei Yuhao, Yan Daren, Han Qiaoyun. STRUCTURAL OPTIMIZATION AND PERFORMANCE ANALYSIS OF U-TUBULAR PHASE CHANGE HEAT STORAGE EVACUATED SOLAR COLLECTOR TUBE[J]. Acta Energiae Solaris Sinica. 2024, 45(9): 451-457 https://doi.org/10.19912/j.0254-0096.tynxb.2023-1647

References

[1] 刘艳峰, 李彤, 李勇, 等. 相变蓄热U型真空管太阳能集热器热性能研究[J]. 太阳能学报, 2021, 42(7): 244-250.
LIU Y F, LI T, LI Y, et al.Thermal performance of U-pipe evacuated tube solar collector with latent heat thermal energy storage[J]. Acta energiae solaris sinica, 2021, 42(7): 244-250.
[2] 李拴魁, 林原, 潘锋. 热能存储及转化技术进展与展望[J]. 储能科学与技术, 2022, 11(5): 1551-1562.
LI S K, LIN Y, PAN F.Research progress in thermal energy storage and conversion technology[J]. Energy storage science and technology, 2022, 11(5): 1551-1562.
[3] 仝仓, 李祥立, 端木琳. 多管式相变蓄热器换热影响因素研究[J]. 太阳能学报, 2019, 40(8): 2299-2305.
TONG C, LI X L, DUANMU L.Study on heat transfer influence factors of multitube phase change thermal accumulator[J]. Acta energiae solaris sinica, 2019, 40(8): 2299-2305.
[4] OGOH W, GROULX D.Effects of the number and distribution of fins on the storage characteristics of a cylindrical latent heat energy storage system: a numerical study[J]. Heat and mass transfer, 2012, 48(10): 1825-1835.
[5] 安玉娇, 高岩, 李德英. U型管集热器流场和热特性的数值模拟[J]. 能源技术, 2010, 31(3): 169-174.
AN Y J, GAO Y, LI D Y.Analysis and simulation study of flow and thermal performance in the U-tube solar collector[J]. Energy technology, 2010, 31(3): 169-174.
[6] ABOKERSH M H, EL-MORSI M, SHARAF O, et al.An experimental evaluation of direct flow evacuated tube solar collector integrated with phase change material[J]. Energy, 2017, 139: 1111-1125.
[7] ALGARNI S, MELLOULI S, ALQAHTANI T, et al.Experimental investigation of an evacuated tube solar collector incorporating nano-enhanced PCM as a thermal booster[J]. Applied thermal engineering, 2020, 180: 115831.
[8] HAMADA M A, EHAB A, KHALIL H, et al.Thermal performance augmentation of parabolic trough solar collector using nanomaterials, fins and thermal storage material[J]. Journal of energy storage, 2023, 67: 107591.
[9] ABO-ELFADL S, HASSAN H, EL-DOSOKY M F. Energy and exergy assessment of integrating reflectors on thermal energy storage of evacuated tube solar collector-heat pipe system[J]. Solar energy, 2020, 209: 470-484.
[10] ESSA M A, ROFAIEL I Y, AHMED M A.Experimental and theoretical analysis for the performance of evacuated tube collector integrated with helical finned heat pipes using PCM energy storage[J]. Energy, 2020, 206: 118166.
[11] MOJTABA TABARHOSEINI S, SHEIKHOLESLAMI M.Modeling of evacuated tube solar collector involving longitudinal fins and nanofluids[J]. Sustainable energy technologies and assessments, 2022, 53: 102587.
[12] 薛花. 相变储能型太阳能真空集热管内相变传热研究[D]. 南京: 东南大学, 2015.
XUE H.Study on phase change heat transfer in phase change energy storage solar vacuum collector tube[D].Nanjing: Southeast University, 2015.
[13] 刘仙萍, 周熙雅, 雷豫豪, 等. 一种带有U型翅片换热管的相变储能太阳能集热管: CN218864509U[P].2023-04-14.
LIU X P, ZHOU X Y, LEI Y H, et al. A phase change energy storage solar collector tube with U-shaped fin heat exchanger: CN218864509U[P].2023-04-14.
[14] WANG Y, GE S X, HUANG B J, et al.A simple route to PVC encapsulated Na₂SO₄·10H₂O nano/micro-composite with excellent energy storage performance[J]. Materials chemistry and physics, 2019, 223: 723-726.
[15] LI C C, ZHANG B, XIE B S, et al.Tailored phase change behavior of Na₂SO₄·10H₂O/expanded graphite composite for thermal energy storage[J]. Energy conversion and management, 2020, 208: 112586.
[16] 刘宇飞, 章学来, 华维三, 等. 相变蓄热式集热器蓄放热数值与实验分析[J]. 太阳能学报, 2017, 38(9): 2486-2492.
LIU Y F, ZHANG X L, HUA W S, et al.Numerical analysis of heat charge and discharge characteristics of solar collectors integrated with phase change thermal storage[J]. Acta energiae solaris sinica, 2017, 38(9): 2486-2492.