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dc.creatorOlufade, Adesola Oluwasijibomi 1989-
dc.date.accessioned2018-04-03T17:45:59Z
dc.date.available2021-04-03T06:05:08Z
dc.date.created2018-02
dc.date.issued2018-04-03
dc.date.submittedFebruary 2018
dc.identifier.urihttp://hdl.handle.net/10388/8487
dc.description.abstractLiquid-to-air membrane energy exchangers (LAMEEs) are a recent development with potential for energy savings in heating, ventilation and air-conditioning (HVAC) applications. Unlike conventional heat exchangers that transfer only heat using plates or tubes, LAMEEs use semi-permeable membranes to transfer both heat and moisture between liquid desiccant and air streams, while preventing cross-contamination between the fluids. However, the porous membranes used in LAMEEs are prone to crystallization fouling from liquid desiccants, and this may compromise the performance of LAMEEs. The research reported in this thesis aims to experimentally characterize crystallization fouling in LAMEEs. Experimental tests are performed to dehydrate MgCl2(aq) solution using two types of membranes. The objectives of the research are to (i) develop and calibrate indirect and non-invasive methods to detect the onset of crystallization fouling in a LAMEE, (ii) identify operating conditions that result in crystallization fouling in LAMEEs, and (iii) identify the evolution of crystallization fouling in membranes. The objectives are met by using non-invasive and invasive methods. The non-invasive methods consist of indirect and direct methods. Three indirect and non-invasive methods are developed to detect fouling by analyzing two measured parameters (moisture transfer flux and resistance). One direct and non-invasive method is used to directly observe the onset of crystallization fouling in the LAMEE. The invasive methods consist of optical microscopy and scanning electron microscopy which are used to characterize the morphology of deposits on membranes, and energy dispersive X-ray spectroscopy which is used to analyze the composition of the deposits. The direct and non-invasive method detects the start of fouling earlier than the three indirect and non-invasive methods by a factor of three to eight, and is used to calibrate and thereby augment the sensitivity of the indirect and non-invasive methods. Sensitivity studies indicate that crystallization fouling in the LAMEE is dependent on both the concentration of the desiccant solution and the relative humidity of air. Furthermore, the results show that reducing the moisture transfer rate through the membrane can minimize crystallization fouling in the LAMEE. Finally, the evolution and mechanisms of crystallization fouling in membranes are delineated.
dc.format.mimetypeapplication/pdf
dc.subjectCrystallization fouling
dc.subjectMembrane
dc.subjectInvasive methods
dc.subjectNon-invasive methods
dc.subjectDetection
dc.subjectMoisture transfer
dc.titleEXPERIMENTAL CHARACTERIZATION OF CRYSTALLIZATION FOULING IN LIQUID-TO-AIR MEMBRANE ENERGY EXCHANGERS
dc.typeThesis
dc.date.updated2018-04-03T17:45:59Z
thesis.degree.departmentMechanical Engineering
thesis.degree.disciplineMechanical Engineering
thesis.degree.grantorUniversity of Saskatchewan
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy (Ph.D.)
dc.type.materialtext
dc.contributor.committeeMemberEvitts, Richard
dc.contributor.committeeMemberTorvi, David
dc.contributor.committeeMemberSumner, David
dc.contributor.committeeMemberGuo, Huiqing
local.embargo.terms2021-04-03


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