Multi-physics simulation of CO2 gas coolers using equivalence modelling

A CFD model to simulate CO2 gas coolers is presented: the adoption of an equivalent approach allows to reproduce the effects of an extended finned surface while drastically reducing the computational effort. The model is validated against experimental results available in the open literature. The contemporary solution of both convection and conduction allows highlighting the impact of conduction along the tubes and the supporting end plates. The model provides satisfactory matching with experimental results: total heating power is forecast within 2.5%, while the maximum temperature deviation between the simulated and experimental heat exchanger curves temperature is 3.8 °C, when the CO2 temperature is as high as 108 °C. This thermal CFD model allows evaluating the 3D effects of the air maldistribution in terms of temperature, heat transfer coefficients, and cooling power, thus opening the way to the simulation and optimisation of complete ventilated finned coil and gas cooling systems. © 2018 Elsevier Ltd and IIR