2022 Volume 39 Issue 1 Pages 35-
In the field of the absorption chillers with LiBr/H2O as its working pair, a small amount of absorbent was mixed in the evaporator to lower the freezing point of the refrigerant and obtain lower temperature output. The purpose of this study is to develop a middle-low temperature absorption chiller that provides 1 to 3 °C chilled water by applying the above method for general hot water-driven single-effect absorption chillers. As the fundamental step of the development, this paper discusses the behavior of the cycle by cycle simulation considering dilute solution in the evaporator. We have developed a cycle simulator that includes the physical and heat transfer characteristics of the dilute solution. “2-step evaporator and absorber” was taken into consideration that is adopted to improve the cooling efficiency. This simulator also draws a Dühring diagram that helps us to understand this cycle. In conclusion, we have found that this cycle has enough margin against refrigerant freezing and solution crystallization by setting appropriate LiBr concentrations in the evaporator. These results lead us to the conclusion that an absorption chiller with 1 to 3 °C output using dilute LiBr solution has sufficient feasibility to be put into practical use.
