HCurve Stream Evaluation Data

Heating/Cooling Curve for Flowsheet Streams

This window is used to specify the evaluation data -- the variable range and the calculation type, for the selected process stream. The calculation type (isothermal, fixed-enthalpy, dew point, bubble point) is selected by the choices you make for the first and the second specifications.

Note: For each stream entry in the Heating/Cooling Curve Main Window, PRO/II will perform only one type of calculation. If more than one type of calculation is required for the same stream, you have to duplicate the stream entry in the main window and then select different calculation methods for each entry.

Usage

From the Heating/Cooling Curve Main Window, select the desired stream in the stream table. Push the corresponding Enter Data button to display this window.

Calculation Table as a Function of Specification Type

First Specification	Second Specification	Starting Point	Increments
Temperature Range	Pressure Increment	User supplied temperature, stream pressure	Equal temperature and pressure increments
	Pressure Range	User supplied temperature, user supplied pressure	Equal temperature and pressure increments
	Dew Point	User supplied temperature, dew point	Equal temperature increments at dew point.
	Bubble Point	User supplied temperature, bubble point	Equal temperature increments at bubble point.
Temperature Increment	Pressure Increment	Stream temperature, stream pressure	Equal temperature and pressure increments.
	Pressure Range	Stream temperature, user supplied pressure	Equal temperature and pressure increments.
	Dew Point	Stream temperature, dew point	Equal temperature increments at dew point.
	Bubble Point	User supplied temperature, bubble point	Equal temperature increments at bubble point.
Pressure Range	Temperature Increment	User supplied pressure, stream temperature	Equal temperature and pressure increments.
	Temperature Range	User supplied temperature, user supplied pressure	Equal temperature and pressure increments
	Dew Point	User supplied pressure, dew point	Equal pressure increments at dew point.
	Bubble Point	User supplied pressure, bubble point	Equal pressure increments at bubble point
Pressure Increment	Temperature Increment	Stream pressure, stream temperature	Equal temperature and pressure increments
	Temperature Range	Stream pressure, user supplied temperature	Equal temperature and pressure increments
	Dew Point	User supplied pressure, dew point	Equal pressure increments at dew point.
	Bubble Point	User supplied pressure, bubble point	Equal pressure increments at bubble point
Enthalpy Change (Adiabatic)	Temperature and pressure Increments	Stream pressure, stream temperature.	Equal pressure and enthalpy increments with final enthalpy evaluated at T = del T * (points – 1) and P = del P * (points-1)
	Pressure and Enthalpy Increments	Stream pressure, stream temperature	Equal pressure and enthalpy increments with final enthalpy evaluated at H = Hi + Hdif
	Pressure Range and Enthalpy Increment	User supplied pressure, stream enthalpy (reflashed at pressure)	Equal pressure and enthalpy increments with final enthalpy evaluated at H = Hi + Hdif
	Temperature and Pressure Ranges	User supplied temperature and pressure	Equal pressure and enthalpy increments with final enthalpy evaluated at user supplied temperature and pressure
	Temperature Increment and Pressure Range	Stream temperature and user supplied pressure	Equal pressure and enthalpy increments with final enthalpy evaluated at T = del T * (points – 1)
Isentropic (Constant Entropy)	Pressure Increment	Stream pressure, stream temperature	Equal pressure increments and constant entropy
	Pressure Range	User supplied pressure, stream temperature	Equal pressure increments and constant entropy
	Temperature Increment	Stream pressure, stream temperature	Equal temperature increments and constant entropy
	Temperature Range	Stream pressure, user supplied temperature	Equal temperature increments and constant entropy

Specification Data

Enter the data for the selections you made for the first and second specifications.

Report Options

You can request the results printout to contain additional data such as Liquid Activity Coefficients, K-Values, etc., by selecting the appropriate options. These selections will apply only to the curve for which you are entering the evaluation data. The first of these options (liquid activity coefficients, etc.) will produce meaningful results only if a liquid-activity K-value method is chosen in the thermodynamic data section of input.

Number of Evaluation Points

You can also select the number of points in the specified temperature/pressure range where the flash calculations are to be performed. The default value is eleven, creating ten equally spaced intervals.

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