A thermodynamic perspective to study energy performance of vacuum-based membrane dehumidification
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Environmental Science and Engineering Program
Water Desalination and Reuse Research Center (WDRC)
Online Publication Date2017-05-13
Print Publication Date2017-08
Permanent link to this recordhttp://hdl.handle.net/10754/623626
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AbstractIn humid environments, decoupling the latent and sensible cooling loads - dehumidifying - can significantly improve chiller efficiency. Here, a basic limit for dehumidification efficiency is established from fundamental thermodynamics. This is followed by the derivation of how this limit is modified when the pragmatic constraint of a finite flux must be accommodated. These limits allow one to identify promising system modifications, and to quantify their impact. The focus is on vacuum-based membrane dehumidification. New high-efficiency configurations are formulated, most notably, by coupling pumping with condensation. More than an order-of-magnitude improvement in efficiency is achievable. It is contingent on water vapor exiting at its saturation pressure rather than at ambient pressure. Sensitivity studies to recovery ratio, temperature, relative humidity and membrane selectivity are also presented.
CitationBui TD, Kum Ja M, Gordon JM, Ng KC, Chua KJ (2017) A thermodynamic perspective to study energy performance of vacuum-based membrane dehumidification. Energy. Available: http://dx.doi.org/10.1016/j.energy.2017.05.075.
SponsorsThe authors gratefully acknowledge the generous funding from the National Research Foundation (NRF) of Singapore under the Energy Innovation Research Programme (EIRP) Funding Scheme (R-265-00-543-279) managed on our behalf by the Building and Construction Authority (BCA). JMG expresses his gratitude to Prof. Kian Jon (Ernest) Chua for his generous and gracious hospitality at NUS during the period of this research.