Figure 3 Solid desiccant- hybrid cooling system
The pre-cooled air by solid desiccant cooling is sent to the vapor
compression air conditioning system. The air is cooled to comfort supply
condition which is specified as point 4 which is sent to the cabin to
address the heat load.
The working of the solid desiccant cooling system is simulated by the
object-oriented programming BLUEJ simulation platform. This is a looping
system and the system achieves steady-state conditions through an
iterative procedure.
For equipment like the desiccant wheel, the desired humidity ratio is
attained through an iterative process that involves incremental
increases in the air humidity ratio. The program continues to run until
it reaches a steady state (∆T<0.001), which means that the
temperature between two iterations must be less than 0.001°C at all the
stages in the solid desiccant loop. Initially, the system was modeled
using ideal process assumptions. Non-idealities in the process are added
later to make the model more effective in making accurate predictions of
outcomes in real-world situations. The operating points of all the
equipment in the loop are given as desired operating conditions via a
notepad.
The system is tested for numerous hot-humid conditions. The operating
conditions where the system is tested are given in Figure 4. The ambient
conditions for which the system is tested are in the humidity ratios of
21, 22, and 28 gkg-1 d.a. These conditions are taken
from the experimental work reported by Venkatesh et al [18].