TY - JOUR
T1 - Performance of adsorbent-embedded heat exchangers using binder-coating method
AU - Li, Ang
AU - Thu, Kyaw
AU - Ismail, Azhar Bin
AU - Shahzad, Muhammad Wakil
AU - Ng, Kim Choon
N1 - Financial support from the National Research Foundation (NRF) Singapore (Grant WBS No. R-265-000-466-281) and King Abdullah University of Science & Technology (KAUST) (project No. 7000000411).
PY - 2016/1
Y1 - 2016/1
N2 - The performance of adsorption (AD) chillers or desalination cycles is dictated by the rates of heat and mass transfer of adsorbate in adsorbent-packed beds. Conventional granular-adsorbent, packed in fin-tube heat exchangers, suffered from poor heat transfer in heating (desorption) or cooling (adsorption) processes of the batch-operated cycles, with undesirable performance parameters such as higher footprint of plants, low coefficient of performance (COP) of AD cycles and higher capital cost of the machines. The motivation of present work is to mitigate the heat and mass "bottlenecks" of fin-tube heat exchangers by using a powdered-adsorbent cum binder coated onto the fin surfaces of exchangers. Suitable adsorbent-binder pairs have been identified for the silica gel adsorbent with pore surface areas up to 680 m2/g and pore diameters less than 6 nm. The parent silica gel remains largely unaffected despite being pulverized into fine particles of 100 μm, and yet maintaining its water uptake characteristics. The paper presents an experimental study on the selection and testing processes to achieve high efficacy of adsorbent-binder coated exchangers. The test results indicate 3.4-4.6 folds improvement in heat transfer rates over the conventional granular-packed method, resulting a faster rate of water uptake by 1.5-2 times on the suitable silica gel type.
AB - The performance of adsorption (AD) chillers or desalination cycles is dictated by the rates of heat and mass transfer of adsorbate in adsorbent-packed beds. Conventional granular-adsorbent, packed in fin-tube heat exchangers, suffered from poor heat transfer in heating (desorption) or cooling (adsorption) processes of the batch-operated cycles, with undesirable performance parameters such as higher footprint of plants, low coefficient of performance (COP) of AD cycles and higher capital cost of the machines. The motivation of present work is to mitigate the heat and mass "bottlenecks" of fin-tube heat exchangers by using a powdered-adsorbent cum binder coated onto the fin surfaces of exchangers. Suitable adsorbent-binder pairs have been identified for the silica gel adsorbent with pore surface areas up to 680 m2/g and pore diameters less than 6 nm. The parent silica gel remains largely unaffected despite being pulverized into fine particles of 100 μm, and yet maintaining its water uptake characteristics. The paper presents an experimental study on the selection and testing processes to achieve high efficacy of adsorbent-binder coated exchangers. The test results indicate 3.4-4.6 folds improvement in heat transfer rates over the conventional granular-packed method, resulting a faster rate of water uptake by 1.5-2 times on the suitable silica gel type.
KW - Adsorption heat transfer
KW - Adsorption isotherms
KW - Binder
KW - Hydroxyethyl cellulose
KW - Silica gel-water
UR - http://www.scopus.com/inward/record.url?scp=84941286925&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatmasstransfer.2015.08.097
DO - 10.1016/j.ijheatmasstransfer.2015.08.097
M3 - Article
AN - SCOPUS:84941286925
SN - 0017-9310
VL - 92
SP - 149
EP - 157
JO - International Journal of Heat and Mass Transfer
JF - International Journal of Heat and Mass Transfer
ER -