public static double CalculateWaterSaturationTemperature(double pressure)
{
double temperature = 1.0e-6;
if (pressure < 1.0e-6)
{
pressure = 1.0e-6;
}
if (pressure <= 611.22) //temperature below the steam table can deal with
//temperature = 193.03 + 28.633 * Math.Pow(pressure, 0.1609);
{
double a = Math.Log(pressure / 611.21);
temperature = a * 240.97 / (17.502 - a) + 273.15;
}
else if (pressure > 611.22)
{
SteamTable steamTable = SteamTable.GetInstance();
temperature = steamTable.GetSaturationTemperature(pressure);
}
/*//use correlation from Perry's to finalize
* else {
* //use simple correlation to do a rough estimation
* temperature = 3816.44/(23.197 - Math.Log(pressure)) + 46.13;
* double old_temp;
* double fx;
* double dfx;
* int i = 0;
* do {
* i++;
* old_temp = temperature;
* //direct iterative method
* //temperature = -7258.2/(Math.Log(pressure) - 73.649 + 7.3037 * Math.Log(old_temp)
* // - 4.1653e-6 * old_temp * old_temp);
* //Newton iterative method--much better convergence speed
* fx = 73.649 - 7258.2/old_temp - 7.3037 * Math.Log(old_temp) + 4.1653e-6 * old_temp * old_temp - Math.Log(pressure);
* dfx = 7258.2/(old_temp * old_temp) - 7.3037/old_temp + 2.0 * 4.1653e-6 * old_temp;
* temperature = old_temp - fx/dfx;
* } while (i < 500 && Math.Abs(temperature - old_temp) > 1.0e-6);
* }*/
return(temperature);
}
