Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/43731
Title: A new approach to enhance the heat and mass transfer of liquid desiccant dehumidification with a titanium dioxide superhydrophilic self-cleaning coating
Authors: Qi, R
Hua, Y
Wang, Y
Lu, L 
Keywords: Contact angle
Heat and mass transfer performance
Liquid desiccant dehumidification
Titanium dioxide superhydrophilic coating
Wetted area
Issue Date: 2016
Publisher: Elsevier
Source: Journal of cleaner production, 2016, v. 112, p. 3555-3561 How to cite?
Journal: Journal of cleaner production 
Abstract: The cooling system with liquid desiccant dehumidification is an energy-efficient and eco-friendly solution for the ever-increasing energy consumption and environmental impact of modern buildings. By significantly influencing the wetted area, the contact angle of the liquid-air interface is critical to the performance of desiccant dehumidification. In this study, to enhance heat and mass transfer performance, a new approach was developed with a titanium dioxide superhydrophilic self-cleaning coating on the dehumidifier surfaces that was made of a highly dispersed paste with nanoscale titanium dioxide particles and activated with ultraviolet light. We first tested the effect of the coatings on samples made of three commonly used materials, SUS304, SUS316, and SUS410, with a 30% LiBr solution and deionized water. Results show that the contact angle on the coated samples dramatically decreased to only 1/7 for water and 1/6 for the LiBr solution compared to uncoated samples. The durability of the coatings was studied experimentally by repeatedly immersing the samples in 30% LiBr, exposing them for 2 months, and reactivating them. It was found that the angle changed slightly for SUS304/316 samples with good anticorrosion performance, whereas the angle increased by 10°-20° for SUS410 samples due to the accelerated catalytic oxidization of the Titanium dioxide coating, which could possibly be solved by precoating an SiO2 compact layer. Furthermore, we found numerically that the wetted area during desiccant dehumidification could be effectively increased by 5-7 times with the coating. Accordingly, the heat exchange rate and moisture removal rate between the air and the desiccant could be increased by 1.2 and 2 times, respectively. Therefore, by dramatically reducing the desiccant contact angle on dehumidifier surfaces and enlarging the wetted area accordingly, the titanium dioxide self-cleaning coating could significantly improve the heat and mass transfer performance of liquid desiccant dehumidification, especially the mass transfer performance. The coatings' manufacture is cheap and facile for industrialization. This measure can be considered an effective and economic way to improve the performance of a dehumidifier and also has other applications in heat exchangers, evaporators, and absorption towers.
URI: http://hdl.handle.net/10397/43731
ISSN: 0959-6526
DOI: 10.1016/j.jclepro.2015.10.115
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

2
Citations as of Oct 7, 2017

WEB OF SCIENCETM
Citations

2
Last Week
0
Last month
Citations as of Oct 16, 2017

Page view(s)

57
Last Week
4
Last month
Checked on Oct 16, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.