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Thermal Performance Analysis of a Triple-Tube Heat Exchanger with Internal and External Conductive Connections

Kuihua Fu
Vol.8, No.3, pp.56-66, 2026 DOI: 10.62051/ijmee.v8n3.08 March 13, 2026
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Abstract: Latent heat storage systems are limited by the low thermal conductivity of phase change materials (PCMs), resulting in prolonged charging and discharging times. To address the issues of a single heat conduction path and thermal coupling imbalance in triplex-tube heat exchangers (TTHX), this study proposes an optimized TTHX with internal and external conductive connections. By integrating fins penetrating the tube walls at the bottom of both annular channels, a direct metallic thermal connection node is established, enabling rapid thermal equilibrium between the inner and outer HTFs. Numerical simulation results show that at an inner-to-outer ratio of 0.7, the melting time is reduced by 35.2%; at a ratio of 0.5, the solidification time is 58.9% shorter than that of the novel TTHX at the same ratio and 41.8% shorter than its optimal solidification time. The performance enhancement is attributed to multi-path heat transfer and the full development of two independent natural convection zones. This study achieves a shift from quantitative enhancement to targeted point-specific enhancement, providing new insights for the design of efficient latent heat storage systems.
Keywords: Triplex-tube Heat Exchanger, Phase Change Material, Heat Transfer Enhancement, Conductive Connection, Melting and Solidification
APA Citation: Kuihua Fu (2026). Thermal Performance Analysis of a Triple-Tube Heat Exchanger with Internal and External Conductive Connections. International Journal of Mechanical and Electrical Engineering, 8(3), 56-66. https://doi.org/10.62051/ijmee.v8n3.08

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