Improvement of heat-mass transfer performance of finned tube heat exchangers via superhydrophilic-superhydrophobic dot arrays for dehumidification in greenhouse environment

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DOI number:10.1016/j.ijheatmasstransfer.2025.128199

Journal:International Journal of Heat and Mass Transfer

Funded by:甘肃省教育厅产业支撑计划；国家自然科学基金

Key Words:Greenhouse dehumidification; Superhydrophilic-superhydrophobic dot array; Low temperature-high humidity; Heat-mass performance; CFD

Abstract:Greenhouses in high-altitude regions often encounter challenges of low temperature and excessive humidity. These result from structural and climatic constraints, leading to high energy consumption for dehumidification. Conventional finned-tube heat exchangers (FTHXs), as core components of refrigeration and dehumidification systems, suffer from inefficient heat transfer and condensate retention, which exacerbate operational losses. To address these limitations, this study proposes a novel finned-tube heat exchanger with superhydrophilic-superhydrophobic dot array (FTHX-SSDA) and introduces a heat and mass transfer enhancement factor (JFhm). A numerical heat transfer model was developed, and computational fluid dynamics (CFD) simulations were conducted to analyze the thermal and hydraulic performance of the FTHX-SSDA under low-temperature, high-humidity conditions. The results demonstrate that, compared to a finned-tube heat exchanger with hydrophilic-surface (FTHX-HS), the FTHX-SSDA exhibits superior performance. Average enhancements include 31.89 % in the heat transfer factor (jh), 21.37 % in the mass transfer factor (jm), and a 1.19 % reduction in the friction factor (f). The JFhm consistently exceeds unity, confirming the excellent thermal efficiency of the FTHX-SSDA. Furthermore, both jh and jm decrease with increasing air-side Reynolds number. However, higher inlet air temperature elevated relative humidity, or lower tube wall temperature improve heat and mass transfer performance. The fitted performance correlation equations for the FTHX-SSDA’s air-side performance under low-temperature, high-humidity conditions were derived. The average errors were 0.6 % (jh), 0.24 % (jm), and 0.1 % (f), indicating high predictive accuracy. These results provide valuable technical insights and serve as a reference for improving and optimizing dehumidification systems in greenhouse settings.

Note:the Department of Education of Gansu Province: Industry Support Plan Project [grant number 2025CYZC-021], the National Natural Science Foundation of China [grant numbers 51868035], and the Department of Education of Gansu Province: Major Cultivation Project of Scientific Research Innovation Platform in University [grant number 2024CXPT-14]

Co-author:Changcong Jiang,Yong Guan,Xiuxiu Zhang,Jianyu Hao,Chenxu Wang,Juanli Ma

First Author:Wanling Hu

Indexed by:Journal paper

Document Code:128199

Discipline:Engineering

Document Type:J

Volume:257:

Page Number:128199

Translation or Not:no

Date of Publication:2025-12-04

Included Journals:SCI