Performance study on a hybrid solid desiccant‐vapor compression air‐conditioning system for hot‐humid ambient conditions

Abstract

The paper focuses on the simulation and testing of a hybrid solid desiccant‐vapor compression air‐conditioning system under different hot‐humid climates. The simulation is carried out by a BLUEJ programming framework. Air at the lowest achievable temperatures from a solid desiccant cooling system is supplied to a standard vapor compression air‐conditioning system (VCAS). The cooling capacities of the hybrid system under three modes 1, 2, and 3, indicating different supply air conditions to the cabin, are reported in the paper. This paper expresses the trade‐off between having comfort conditions and reasonable comfort conditions inside the cooling space with energy efficiency as the inflection point. The more the study is moved towards the point of energy efficiency, the higher the reduction in the cooling capacities of the vapor compression air conditioner. This is demonstrated by the cooling capacity savings when the system is operated in three modes namely 1, 2, and 3. The substantial energy savings provided by Mode 1, Mode 2, and Mode 3 are 71%, 57%, and 37%, respectively. If the system is made to provide substantial cooling and focuses deeply on cooling capacity savings, then the system could save up to 77% in the cooling capacity of the vapor compression air‐conditioning system. If the system is made to operate solely with the milestone of comfort cooling for the occupants with any substantial savings in the cooling capacity of the vapor compression air‐conditioning system, then Mode 3 would deliver the milestone and give savings in the cooling capacities from 32% to 41% which is a significant savings. From the results of the performance study, it is inferred that the hybrid system provides significant energy savings compared to a standard air conditioner, especially in hot‐humid ambient conditions. The solid desiccant cooling system thus establishes itself as an effective pre‐cooler unit for a VCAS. The hybrid solid desiccant air‐conditioning in the paper is analyzed from the aspects of savings in cooling capacities of an existing vapor compression air‐conditioning system and comfort cooling. This is a newer operational approach, especially for using this hybrid solid desiccant cooling system for ambient humidity ratios greater than 15 kg−1 d.a.