Repsol Refinery – Splitter V&V

Consultancy for vibration analysis – structural damping

Vibrations Assesment and simulation

In the commissioning of the Propylene Splitter (C-5606) installed in the REPSOL Complex located in Tarragona (Spain), a problem of vibrations in the equipment was detected due to Vortex Shedding phenomenon. Large displacements were detected on September 2016. Damping was experimentally measured, detecting a very low critical damping in the tower (0.05%).

The aerodynamic phenomenon of Vortex Shedding (vibration problem) has historically occurred in a substantial number of slender structures. This type of dynamic phenomena deserves a meticulous analysis of slender equipment and tall buildings, because it can produce undesirable behavior.

Any fluid flow such as wind passing a structure may cause unsteady flow patterns due to vortex shedding. This may lead to oscillations of slender elements perpendicular to their longitudinal axis.

Dynamis Added Value Proposition

Dynamis has engineered a TLD (Tuned Liquid Damper) in order to reduce the amplitude of the displacements. It is important to note that tuned liquid dampers (TLDs) are based on the same principle as tuned dampers (TMD), with the main difference being the use of fluid as the dissipating system. Tuned Liquid Damper TLD was design as two rectangular boxes, which are partially filled with a water/glycol mixture.  The boxes are specially designed to maximize the damping effectiveness of the fluid that is contained by the damper.

DYNAMIS ASSOCIATES built finite element models to accurately perform dynamic analyses and validate the design of the tuned liquid damper.

The analysis performed by DYNAMIS lead the Liquid tunned damper TLD. This analysis was based in Finite Element modelling and contemplated several scenarios such as: corroded / not corroded, simplified models of mass distribution, with / without TLD system…