THERMAL SCIENCE

International Scientific Journal

Suola Shao

,

Chengcheng Xu

THERMAL PERFORMANCE INVESTIGATION OF AN ALUMINUM FANLESS THERMAL STORAGE INDOOR HEAT EXCHANGER UNDER MULTIPLE OPERATION PARAMETERS: AN EXPERIMENTAL AND NUMERICAL STUDY

ABSTRACT
The direct-condensation indoor heat exchanger was an effective heating method for winter heating. However, the metal thermal strength and pressure-bearing capacity of the previous steel panel were weaker than that of aluminum materials. Consequently, a novel aluminum fanless thermal storage indoor heat exchanger (AHE) is proposed for the air-source heat pump (ASHP) heating system. The model is established to explore the heating performances of the novel direct-condensation indoor heat exchanger. Compared with experimental data, the deviation of the predicted heat dissipation changes from –2.4% and 3.6%, verifying the model’s reliability. To investigate the thermal potentials of the AHE under multiple operation parameters, a total of 66 cases were conducted. Results show that the ascendant condensation temperature and refrigerant flow rate are beneficial for the improvement of the heat exchange performance. Meanwhile, the increased condensation temperature also contributes to decreasing flow losses. In simulations, the average temperature difference between the refrigerant and panel surface is 9.7°C. The maximum temperature difference of adjacent layers of the AHE is 6.3°C, occurring between the copper tube and the water layer. Based on the simulated values, a thermolysis correlation was proposed for the AHE to predict the heat dissipation under multiple operation parameters. This study provides a stable and reliable direction-condensation heating terminal for ASHP systems. The results of this study are beneficial for the promotion and application of the direction-condensation heating terminal.
KEYWORDS
Air source heat pump, Indoor heat exchanger, Model verification, Thermal performances, Thermolysis correlation
PAPER SUBMITTED: 2024-05-27
PAPER REVISED: 2025-01-26
PAPER ACCEPTED: 2025-02-02
PUBLISHED ONLINE: 2025-03-08
DOI REFERENCE: https://doi.org/10.2298/TSCI240527029S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2025, VOLUME 29, ISSUE No. 5, PAGES [3759 - 3774]
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Thermal performance investigation of an aluminum fanless thermal storage indoor heat exchanger under multiple operation parameters: An experimental and numerical study

© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence