Heat Exchanger Performance Specification
The performance specification for a heat exchanger can be specified in a number of ways as listed in the following table. The actual choices available will depend on the Heat Exchanger Type and the streams selected for the hot and/or cold sides.
Heat Exchanger Specification |
Exchanger Type |
Area * U-value (Lumped Product) Area and U-value (separate values) Duty (Overall Exchanger) Minimum Internal Temperature Approach (MITA) |
two sided two sided one and two sided two sided |
Temperature Approach Specifications Hot Inlet – Cold Outlet Hot Outlet – Cold Inlet Hot Outlet – Cold Outlet Minimum of (Hot out – Cold in) and (Hot in – Cold out) |
two sided two sided two sided two sided |
Hot Side Specifications Hot Product Liquid Fraction Hot Product Temperature Hot Product Temperature drop below drop bubble point Hot Product Temperature rise above Dew point Hot product temperature drop |
one and two sided one and two sided one and two sided one and two sided one and two sided |
Cold Side Specifications Cold Product Liquid Fraction Cold Product Temperature Cold Product Temperature drop below Bubble point Cold Product Temperature rise above Dew point Cold product temperature rise |
one and two sided one and two sided one and two sided one and two sided one and two sided |
Usage
From the Simple Heat Exchanger Main Window, push the Specification button to display the Heat Exchanger Specification window.
1. Select one of the heat exchanger specifications.
2. In the Value data entry field, enter the value for the specification selected (except for the individual "U and Area" specification, where this field is not available).
3. Enter the Relative convergence tolerance to help speed the convergence. The default value is 0.001.
4. If you have selected the individual "U and Area" specifications, enter the individual values for Area and overall heat transfer coefficient (U - Value). For other specifications, these values are optional and if one value is entered, the other will be calculated and is not available.
5. An upper limit on the heat transfer of the exchanger can be imposed by entering a value for Maximum Allowable U*A. This value cannot be used if you have selected either "overall U*A" or individual "U and Area" specifications.
Note : If one side of the exchanger is attached to a column the duty can be calculated either by the column or the heat exchanger. The default specification for this case is "In the column" since it is suggested that the column be allowed to calculate the duty, since the column convergence is considerably enhanced in PRO/II.
Related Topics
Simple Heat Exchanger - Technical Information