Absorption refrigeration using low-grade solar heat

geothermal heat or industrial waste heat as driving heat source is an effective way to achieve energy saving and emission reduction. A new working pair of CaCl2-LiCl/H2O

which has an excellent refrigeration absorption characteristic

was studied by measuring its crystallization temperature and vapor pressure with different mass ratios of CaCl2∶LiCl. The results showed that CaCl2-LiCl(2∶1)/H2O with a mass ratio of 2∶1 was the most suitable working pair for an absorption refrigeration system. Compared with LiBr/H2O

under the same refrigeration conditions

the required driving heat source temperature

that is

the required generation temperature for CaCl2-LiCl(2∶1)/H2O was 5.8℃ lower

COP and exergy efficiency for CaCl2-LiCl(2∶1)/H2O were 0.041 and 0.052 higher

respectively. Furthermore

the cost of working pair was greatly reduced. In addition

the crystallization temperature

saturated vapor pressure

density

viscosity

specific heat capacity

specific enthalpy

and corrosivity of CaCl2-LiCl(2∶1)/H2O were measured systematically. Compared with other working pairs using CaCl2 as the main component

CaCl2-LiCl(2∶1)/H2O had a relatively low viscosity and low corrosion rates for carbon steel and copper

so it could meet the requirements of practical engineering application.