Abstract
The existing combined absorption refrigeration and liquid desiccant dehumidification systems have the disadvantages of small temperature difference in waste heat utilization and high cost of working pair. For effective and deep utilization of low-grade heat below 80 degrees C, a novel air conditioning system cascade driven by waste heat is established. In this system, the low-grade heat is used to drive an absorption chiller to produce chilled water for air cooling and then drive a liquid desiccant system for air dehumidification. The cheaper and non-corrosive KCOOH solution is selected as the comparative working pair of LiBr solution to conduct the experimental study in the system. Operation parameters such as inlet temperature, flow rates of both hot water and cooling water that directly affect the application of the system are studied. The results show that the system can be driven by 80 degrees C hot water, which is much lower than that of the conventional single absorption refrigeration system. Besides, both working pairs can be used for the system. As the inlet parameters of supply air are fixed, the cooling capacity of KCOOH solution is 10% lower than that of LiBr solution. The KCOOH solution has comparable COP compared to LiBr solution only when the dilute solution flow rate is low. The conclusion is summarized that considering the much lower cost, the KCOOH solution is a promising working pair for this novel air conditioning system, nevertheless, the structure of this system needs to be redesigned to match this working pair.
NSTL
Elsevier