The simulation is provided for pedagogical purposes only. It should not be employed in formal design calculations, or for summative college assessments. Pressures are restricted to the range between 0.4 and 20 bar.
The user is warned when the degree of superheat exceeds 100K or when the pressure exceeds 20 bar. You cannot plot points where the temperature is less than its saturation value - the POI is moved horizontally onto the liquid saturation line. For the T-s plots, the corresponding "no-go" zone is shaded white. (Note that the impact of pressure on the physical properties of liquid ammonia is very small - if the liquid is subcooled then you can use the properties at the saturation pressure corresponding to the subcooled temperature).
Full details of data sources are here . The Antoine coefficients relating saturation pressure to temperature are available on the NIST webbook [reference]. The enthalpy of superheated vapour with saturation temperatures of 223K and 273K are fitted to quadratic functions. Enthalpies at different pressures can be extrapolated using 'general thermodynamic relationships' Rogers and Mayhew. The remaining data are available in Ziegler and Trepp.
There is no option to change scales on the temperature, entropy, pressure and enthalpy axes.
NA
NIST webbook - go to 'phase change data' and look up Antoine coefficients. .