HXAIR - Technical Information

Air Cooled Heat Exchanger (ACE) is Heat Transfer equipment, which uses air as the cooling fluid. Air cooled Heat exchangers are used in many process industries, especially in Petro chemical industries.

Air Cooled Heat Exchanger have two sides, one is tube side, which is a process side and the other one is shell side, which is basically air side. Air is supplied to the unit operation using fans. These fans can be either placed at the bottom or top of the unit operation. If the fan is situated at the top then it is called Induced draft type and if it is at the bottom of the ACE then it is Forced draft type arrangement. Technically, in Induced draft type exchangers the tube side is on the intake section of the fan. For Forced arrangement the tube section is at the discharge side of the exchanger. The air-cooled heat exchanger employs tubes on the process side and these tubes can be bare tubes or finned tubes, depending on the heat transfer requirements.

Two calculation options available in PRO/II for simulating Air Cooled Heat Exchanger are

Rating mode
Design mode

Rating mode With None specification: specify the area of the unit and its fouling resistance. PRO/II rates the unit and predicts both product stream temperatures and the unit’s duty

Or:

With specification: specify the duty of the exchanger or one of the product stream temperatures or one of the approach temp or the Tube side Liquid fraction. PRO/II calculates:

1. the area required to achieve the duty with the given fouling factor

2. the fouling factor required to achieve the duty with the given area

Design mode determines the surface area and exchanger dimensions for specified process conditions.

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