Cross flow heat exchangers - air cooler (AC)
Design of cross flow heat exchangers with bare or finned tubes
In general, heat transfer in rectangular tube bundles with rectangular or circular finned tubes as well as heat exchanger batteries can be calculated. The given area reserve and the actual outlet temperatures of the media (often differing from the required temperatures) are determined. To determine the temperature distribution in cross-flow, a sophisticated cell method is used. The geometrical data of the tube sheet can be saved as CAD file.
The program determines the physical properties of several media automatically. Specific properties can be integrated into the program by 'Free Input' Property modules, which were especially created by user request, can be integrated into the program. This also holds for condensing or evaporating media. For other media, which are not subject to phase changes, the user enters mean values for the necessary properties.
By integrating our property data generator program PROPER it is possible to determine properties and phase equilibria of more than 800 substances.
Multi-pass bundles and shells are considered. Tube pitch and tube arrangement can be selected freely. It is possible to use bare tubes, circular finned tubes, internally finned tubes, tubes with twisted-tape inserts, tubes with spiral fins with ripples, rectangular finned tubes (fin plate) and corrugated tubes. Shells can be cylindrical or rectangular.
Basis of the calculation approaches is the VDI Heat Atlas. When cooling air, flue gas or humid gases, condensation of the humid part at the cold wall is considered. The thermal transfer is calculated by using the method of  and the amount of water or the humidity are calculated as well.
If the wall temperature is below zero or if there is a huge amount of condensed water the program displays warnings. Evaporation of pure substances in the tubes is calculated according to the mathematical approaches of the VDI Heat Atlas .
Calculation of total or partial evaporation and total or partial condensation is possible.