DOI: 10.1615/ICHMT.1986.IntSympHMTinRefCryo
ISBN Print: 978-3-54017-957-3
Evaluation of Thermodynamic Properties of Binary Fluid Mixtures
ABSTRAKT
For operation of absorption systems, the design engineer should have on hand suitable working fluids and knowledge of their thermodynamic and transport properties. For absorption systems such fluids should contain one or more volatile components- the refrigerant and one or more high-boiling components, generally termed absorbents. The latter should have a high chemical affinity for the former.
Conventionally, two working fluids have been extensively used in commercial absorption installations. One contains ammonia as the volatile component and water as the absorbent. In the second, water is used as the volatile phase, and aqueous solutions of lithium bromide as the absorbents. In both cases, the volatile components are characterized by a high enthalpy of condensation or evaporation, a property which permits construction of compact condenser and evaporator components within the absorption machine. However, each of these working fluids has specific shortcomings, which appreciably limit their usefulness. Thus, the ammonia-water combination is corrosive to copper. Ammonia is a toxic fluid with strongly irritant properties. In addition, it is claimed that ammonia decomposes thermally to nitrogen and hydrogen at temperatures above about 180°C.