The heat exchanger is a critical equipment for the cooling system in many industrial processes. Its effectiveness maintenance, strongly compromised by the inevitable fouling on the surfaces of the heat exchanger, is of extreme importance to assure effectiveness of the productive process. This Course Conclusion work simulates the flow of the heat exchanger’s work fluid (water), which is also the fluid that transports the cleaning artefacts of an innovative device conceived in PUC-Rio to perform the online (during operation) cleaning of the heat exchanging surfaces of the heat exchanger, a device which allows the heat exchanger’s cleaning without requiring the technical stop of the hydro generator. The flow simulation accomplished the purpose of guiding the incorporation of incremental innovation in the online cleaning device’s constructive project, especially in the injection chamber for the cleaning artefacts used (abrasive spheres). Two computational tools were used in development, a CAD 3D software developed by SolidWorks Corporation (used to build the mechanical project) and the ANSYS Software and its apps used to generate the computational mesh and the physical simulation (solution of the continuity and Navier Stokes equations). The results obtained were extremely strategical to guide the changes in the innovative heat exchanger cleaning device’s, OnLineCleaner, Horizontal Chambers Model, constructive project.