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Adsorption Desalination: A Novel Method 419
out that as the inlet temperature of evaporator is raised, near to the ambient temperature, the
SDWP could be increased to almost two- or threefold.
4.4. Effect of Heat Source Temperature on the Cycle Performance
Figure 9.16 shows the effect of the hot water inlet temperature on the cycle COP and
SDWP for two half-cycle times of 180 and 300 s. It is noted that the SDWP increases linearly
with the increase of hot water inlet temperature at both cycle times. The improvement is
attributed to the increase in refrigerant flow within the AD cycle at higher driving source
temperatures. The rate of increase in COP is higher when regeneration temperature is below
80 C and beyond this temperature, the increase in COP is slower. This happens due to the fact
that the requirement of heat input becomes significantly large when the temperature difference
between heat source and heat sink becomes high.
4.5. Effect of Cooling and Chilled Water Temperature on the Cycle Performance
Effects of chilled and cooling water inlet temperatures on the cycle performance are shown
in Fig. 9.17. The SDWP can be improved by about 10% when the cooling water inlet
temperature decreases by about 1.6 C. This is because of the increase in adsorption capacity
of silica gel with the decrease in adsorption temperature. It is noticed that the SDWP also
increases with the increase in chilled water inlet temperature, which implies that if the chilled
water temperature is raised, further enhancement of the SDWP is possible.
Fig. 9.16. Effects of the hot water temperature on the system performance (40).