Template:HXSizeCalc Theory

The side calculation is based on the actual duty of the {{{UnitOp}}}. The calculations are for user information only, thus they have no affect on the mass and energy balance of the model.

The basic equation used for these calculations is:

(2) [math]\displaystyle{ \mathbf{\mathit{Q=UA\boldsymbol{\Delta}T_{LM}}} }[/math]

where

Q - Rate of Heat Transfer

U - Overall coefficient of Heat Transfer

A - Area available for Heat Transfer

[math]\displaystyle{ \mathbf{\mathit{\boldsymbol{\Delta}T_{LM} = \cfrac{\Delta T_2 -\Delta T_1}{ln \left( \cfrac{\Delta T_2}{\Delta T_1} \right) }}} }[/math] - Log Mean Temperature Difference (LMTD)

For Counter Current Flow [math]\displaystyle{ \; \Delta T_2 = T_{H_{in}} - T_{C_{out}} \quad }[/math] and [math]\displaystyle{ \; \Delta T_1 = T_{H_{out}} - T_{C_{in}} }[/math]

• based on the above equation, variables are: HTC, area and LMTD. User can specify values for two of these variables, SysCAD will calculate the third term using the {{{UnitOp}}} duty.