Numerical Investigation of the Performance of a Forced Draft Air-Cooled Heat Exchanger

Abstract

This paper details the design, validation and verification of two implicit modelling techniques used to model an Air-Cooled Condenser (ACC) in the computational fluid dynamics (CFD) code environment of OpenFOAM (Open Source Field And Manipulation). The actuator disk model was chosen as the axial flow fan model and the heat exchanger model was implemented as an A-frame, or Delta frame, heat exchanger commonly found on power stations. Both models were validated and verified. A 30 fan ACC was verified against previous literature. The results for all validation and verification procedures showed good agreement with respective data. Three different fan configurations in an ACC were compared at different wind speeds namely the A-fan, B2a-fan and a Combined ACC. The study showed small differences between ACCs with regard to fan and thermal performance. However, the B2a-fan ACC consumed 20% less power than the A-fan ACC and 3–10% less power than the Combined ACC. This performance increase was most prominently show-cased by the increased heat-to-power ratio with the B2a-fan exhibiting heat-to-power ratios of 110 W/W compared to 96 W/W for the A-fan.