Rigorous Heat Exchanger - Film Coefficient Data
Use this window to enter data for shell side, tube side and overall film heat transfer coefficient data. These data provide adjustment factors and override values for the heat transfer coefficients. All the data items in this window have default values.
Usage
Overall U-value Estimate
If you specified the Calculation Type Rating on the Rigorous Heat Exchanger Window, the calculation of overall heat transfer coefficient is iterative. You may enter an initial estimate which may speed up calculations.
Overall U-value Scale Factor
You may enter a multiplier which PRO/II applies to all heat transfer coefficients, whether rigorously calculated or input on this window. Use this entry to match plant data more closely.
This scale factor is applied in addition to the individual film coefficient scale factors.
Two Phase Heat Transfer Coefficient Method
You may select the method to calculate the two-phase heat transfer coefficient. Following are the available options to be selected from drop-down list.
Chen - Modified Chen Vaporization method
HEX5 - Algorithm used in versions 7.1x and earlier.
Tubeside and Shellside Data
You may enter data for heat transfer coefficient and fouling for each side of the exchanger.
Film Options
You may enter either a scale factor or a film heat transfer coefficient
Scale Factor: Enter a factor to be applied to the rigorously calculated film coefficient for this side of the exchanger. This scale factor is applied in addition to the overall film coefficient scale factor.
Coefficient: Enter a value of coefficient to override the rigorously calculated coefficient for this side.
Fouling Resistance
If you selected Rating on the Rigorous Heat Exchanger Window, this value is used to calculate the overall heat transfer coefficient.
If you selected Fixed Duty or Tube Outlet Temperature or Shell Outlet Temperature on the Rigorous Heat Exchanger Window, PRO/II uses this value to calculate the area required to meet the specification. PRO/II also calculates the overall fouling resistance required to meet the specification using the defined area.
Fouling Thickness
You may enter the thickness of the fouling layer to model its effect on the pressure drop.
How to get to this window
The Film Coefficient Data window is accessed by pushing the Film Coefficients button on the Rigorous Heat Exchanger Window.