Performance Evaluation of Pyramidal Fin Arrays Produced by Additive Manufacturing via Cold Spray on Wire Mesh Compact Heat Exchangers

Heat exchangers (recuperators) are used to preheat gas turbine inlet gas. New wire mesh heat exchangers, have pushed the thermal efficiency of these components, but their commercial viability is limited by the production costs. Furthermore, fin production is usually restrained to a single type of material, which for high service temperature applications is usually high cost alloys.

To remedy these problems, near-net shape fin arrays have been produced via additive manufacturing using Cold Spray on bond coats that seals a wire mesh recuperator. The fins and bond coats microstructures were examined through SEM and performance was investigated for several types of bond coat production methods and roughness. Investigation of fin arrays with different materials along the length of the heat exchanger was performed. Changing materials from a high cost/ service temperature to a low cost/ service temperature material allows for significant cost saving opportunities and weight reduction of the recuperator.