Project: NR2 North Rankin 2 Offshore Platform, CFD Analysis of Suction Piping

Client: Woodside Energy, Australia

Completed: 2011

Project Description:

Computational Fluid Dynamics (CFD) Analysis Of Suction Piping Of Tempered Water Pumps

Woodside Energy Limited (WEL) has installed four (3 working + 1 Standby) tempered water re-circulation pumps for the NR2 Development Project. These pumps are double volute, with a horizontally split casing, vertically mounted and driven by 700kW motors. There was concern about too many bends in the suction piping, which could possibly cause uneven flow distribution between top and bottom impeller eyes leading to vibrations and reduced bearing life.

Project Deliverables:

Access Petrotec carried out CFD analysis, using ANSYS FLUENT software. A CFD model of the suction piping was constructed from the exit flange of the expansion tank to the suction flanges of all four pumps. The extent of the model was chosen to assess the single issue of performance of the baffle to give equal flow distribution to top and bottom impeller eyes.

CFD simulations were conducted for 100% rated flow shared between 3 pumps and for the worst case scenario when 50% rated flow is split between 2 pumps. Flow distributions for all possible operating combinations were simulated to determine velocity distribution across the pumps’ suction flanges. Velocity distribution was then integrated to calculate exact flow distribution between top and bottom impeller eyes of all the tempered water re-circulation pumps.