Experimental Analysis of Flow Induced Vibrations in a Helical Coil Heat Exchanger Test Facility for SMR Applications

Abstract

The study is of paramount importance for understanding Flow-Induced Vibration in Helical Coil heat exchangers application in Small Modular Reactors. The study can support design optimization for more stable, safer, and efficient design considerations. The experimental research defines the system response to one degree of freedom (crossflow) of fluid flow at different Reynolds corresponding to 0.14 m/s, 0.28 m/s, and 0.44 m/s inlet velocities. Related observations in terms of operational vibration displacement ranges, Inline and Staggered gap velocities, vortex shedding frequency, Strouhal Numbers, and the scales of turbulence are studied. The transverse pitch ratio is constant (b=2.98), whereas the lateral pitch ratio varies. Reynolds Numbers for Inline configuration were 3500, 7000, and 11000. The investigation involved experimental setup, including the Helical Coil Heat Exchanger HCHE test section, High-Speed camera setup, Image Processing of frame samples, MATLAB digital recognition, and Center Tracking coding. Noise reduction and sensitivity analysis were performed for ~1178 frame samples for each test. Transverse and Axial displacement ranges of the tube influenced by FIV were determined. Fast Fourier Transform (FFT) and Power Spectrum Density (PSD) were employed to identify accurate Shedding frequencies. The further study incorporated turbulence intensity to explore flow behavior within Strouhal values.