Flex with confidence: condition monitoring of rotary flexible hose assemblies through vibrations and spectrogram analysis

Kurzfassung

This paper describes the implementation and first investigations of vibration measurements on two rotary flexible hose assemblies (RFHA, flexible pipe connectors) at the REPA test rig at Plataforma Solar de Almeria. These assemblies are critical components of parabolic trough collector (PTC) plants, and reactive maintenance is the current state of the art, which causes downtime and therefore operating expenses (OPEX) extra costs. A standard REPA aging campaign involves conducting 10,000 mechanical cycles to simulate the 25-year lifespan of the test component under specified temperature and pressure conditions. The data shows that aging has an impact on the mean vibration measurements values which tend to decrease before stabilizing. It was found that the position of the vibration sensor has little effect on the vibration profile itself but on its magnitude. Concerning the traverse movements, the translation movement speed has a significant impact on the vibration profile, while piston rotation changes have a limited effect. The paper concludes that vibration analysis and condition monitoring have to be taken with extreme care due to the complexity of the system and the multiple sources of vibration.