Experimental and Numerical Analysis of a PCM-Supported ...

Figure 3.3: Sketch of the locally established multi-effects of heating and 58
humidification in the evaporator
Figure 3.4: Dependency of air moisture carrying capacity on the temperature 59
Figure 4.1: Schematic layout of the PCM-Supported HDH desalination unit 64
(AquaTube) and operation cycle
Figure 4.2: illustration of heat and mass transfer flow between different 65
components on one packing element; (a) Evaporator, (b) Condenser, (c)
External PCM thermal buffer
Figure 4.3: Schematic of heat transfer in the external PCM thermal buffer; (a) 68
Layout of the PCM packed bed, (b) energy balance over a control volume
Figure 4.4: Schematic of heat and mass transfer in the evaporator; (a) Layout 72
of the evaporator, (b) energy balance over a control volume
Figure 4.5: Schematic of heat and mass transfer in the condenser; (a) Layout 78
of the condenser, (b) energy and mass balance over a control volume
Figure 4.6: Effective heat transfer coefficients obtained with different Nusselt 86
number correlations.
Figure 4.7. Schematic of a semi-infinite domain undergoing phase change 90
Figure 4.8: Linearization of air saturation enthalpy 94
Figure 4.9: Counter current cooling tower operating lines 94
Figure 5.1: Block diagram for the test setup 105
Figure 5.2: Test apparatus and prototype of PCM based HDH system 105
Figure 5.3: Locations of measured parameters 106
Figure 5.4: Thermal behavior of PCM system, top: evaporator, bottom: 112
condenser
Figure 5.5: Thermal behavior of empty spheres system, top: evaporator, 112
botom: condenser
Figure 5.6: Qualitative illustration of temperature profiles in the evaporator 116
Figure 5.7: Qualitative illustration of ideal temperature profiles, left:
116
evaporator, right: condenser
Figure 5.8: Average inlet and outlet liquid and gas temperatures for
117
experiment type (1), Top: Evaporator, Bottom: Condenser
Figure 5.9: Evolution of productivity and GOR for PCM and Empty balls 118
packing elements
Figure 5.10: Comparative productivity; (a) 78cm packed height, (b) 39cm 120
packed height and Comparative GOR; (c) 78cm packed height, (d) 39cm
packed height
Figure 5.11: Comparative productivities for PCM, Empty spheres, and Hiflow 122
rings packing media for 0.38m packing height (for two hours of steady state
operation)
Figure 6.1: Flow diagram and control logic of the simulation model 129
Figure 6.2: Evolution of inlet and outlet liquid and gas temperatures for PCM 133
packing height 78cm; Top: evaporator, (b) Bottom: condenser
Figure 6.3: Evolution of solid phase temperatures for PCM packing height 134
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