HXAIR - Fins Options

Use this window to enter details of the FINS Options Window where you enter data related to the Fins. The User can select a Finned Exchanger or a Non-Finned Exchanger. On selecting the Non-Finned Exchanger, all Fins related parameters are disabled. On selecting a Finned Exchanger, parameters like Number of Fins, Fin Height, Fin Bond Resistance and Fin Efficiency will be enabled. PRO/II defaults to Non-Finned Exchanger.

RANGE:

NUMBER OF FINS - => ZERO

EFFCIENCY - SHOULD BE INBETWEEN 0.0 AND 100

HEIGHT ABOVE ROOT - => ZERO

THICKNESS - >ZERO

AREA PER LENGTH - => ZERO

BOND RESISTANCE - => ZERO

By default the Air Cooled Exchanger is non-finned service. Using the Radio buttons available in the FINS DEW, the user can select the Finned type exchanger or Non-Finned exchanger. There are no defaults for Number of Fins per Unit length. User can enter the Number of Fins per unit length when the Finned Exchanger is chosen. The remaining fields like Fin Height, Fin Thickness and Bond Resistance has default values. When the user selects the Non-Finned Exchanger all the fins related fields will be disabled.

Usage

Fin Data

Enter radial high or low-fin data. PRO/II rigorously calculates the fin performance from the fin dimensions or fin area. You can also specify the fin efficiency.

Number of Fins

Enter the number of radial fins per inch (English input units) or per meter (SI/Metric input units).

Height

Enter the fin height in inches or mm. Otherwise; PRO/II calculates the height if you specify both the Root OD and Tube OD. If you do not specify enough information for the fin height, PRO/II uses a default height of 0.625 inches.

Fin Area

Specifies the Fin Area per Unit length of the tube. The entry is used to compute the Fin Area in place of fin geometry supplied. There is no default. No consistency check is made between this entry and the area value determined from the number of fins, fin height and fin thickness.

Bond Resistance

Specifies fin bond resistance between the exchanger fins and the tube outer diameter. The default is 0.0 hr-ft2F/Btu (English input units); 0.0 hr-m2-c/Kcal (Metric input units); 0.0 m2-K/W (SI input units).

Fin Thickness

Specifies the fin thickness. The default is 0.017in (English input units), or 0.4332mm (Metric and SI input units)

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