Development of thermo-physical properties of aqua ammonia for Kalina cycle system

Ammonia-water mixture is a working fluid used in Kalina cycle system (KCS) and vapour absorption refrigeration (VAR) plants. Unlike for pure components, binary mixtures additionally need mixture concentration to assess thermodynamic properties. In a binary vapour power cycle, two working fluids have been used one with good high-temperature characteristics and another with good low-temperature characteristics. Binary vapour cycle is used to increase the overall plant efficiency. In ammonia-water mixture, ammonia boils at low temperature as it has low boiling point. The components considered should not be toxic and dangerous to human life. The binary fluid considered must be non-corrosive to the metals used in power plants. Ammonia-water mixture as zeotropic nature will have the tendency to boil and condense at a range of temperatures possessing a closer match between heat source and working fluid mixture. Thermodynamic properties have been generated from correlations and derivations and formed as MATLAB subroutines. These properties are used in thermodynamic evaluation of KCS plants. The temperature-concentration, specific volume-concentration, enthalpy-concentration, entropy-concentration and exergy-concentration graphs for ammonia-water mixtures are plotted up to 100-bar pressure.