Study on a Quaternary Working Pair of CaCl(2)-LiNO(3)-KNO(3)/H(2)O for an Absorption Refrigeration Cycle

When compared with LiBr/H(2)O, an absorption refrigeration cycle using CaCl(2)/H(2)O as the working pair needs a lower driving heat source temperature, that is, CaCl(2)/H(2)O has a better refrigeration characteristic. However, the crystallization temperature of CaCl(2)/H(2)O solution is too high and its absorption ability is not high enough to achieve an evaporation temperature of 5 °C or lower. CaCl(2)-LiNO(3)-KNO(3)(15.5:5:1)/H(2)O was proposed and its crystallization temperature, saturated vapor pressure, density, viscosity, specific heat capacity, specific entropy, and specific enthalpy were measured to retain the refrigeration characteristic of CaCl(2)/H(2)O and solve its problems. Under the same conditions, the generation temperature for an absorption refrigeration cycle with CaCl(2)-LiNO(3)-KNO(3)(15.5:5:1)/H(2)O was 7.0 °C lower than that with LiBr/H(2)O. Moreover, the cycle’s COP and exergy efficiency with CaCl(2)-LiNO(3)-KNO(3)(15.5:5:1)/H(2)O were approximately 0.04 and 0.06 higher than those with LiBr/H(2)O, respectively. The corrosion rates of carbon steel and copper for the proposed working pair were 14.31 μm∙y(−1) and 2.04 μm∙y(−1) at 80 °C and pH 9.7, respectively, which were low enough for engineering applications.