CFD study - Gas Scrubber / KO Drum - Kranji Solutions

Описание: This movie shows a Computation Fluid Dynamics simulation of a Gas Scrubber / KO Drum. For more CFD troubleshooting information see also http://kranjisolutions.com.

BUSINESS PROBLEM:
An engineering contractor requested Kranji solutions to perform a CFD simulation of a new-build Gas scrubber / KO drum for a FPSO (Floating Production Storage and Offloading unit).

The Gas Scrubber including the proposed inlet piping was designed by the contractor. The contractor came up an undesirable inlet piping having a 45 degree out of plane elbow just upstream of the inlet nozzle. The liquid loading to the Gas Scrubber is severe, hence the liquid was modelled as a separate phase, resulting in a two phase CFD simulation. Ship motions (accelerations, periods and distances from Center of Rotation) were taken onboard in the simulation.

ANALYSYS
The process flow and the ship motions were both incorporated in one simulation to ensure a proper fit with the actual process and motion conditions.
Inlet momentums and Meshpad K-factors are all within limit, however also in this case, the role of the inlet piping is underestimated. Analytical calculations of the inlet piping result in a “Stratified Wavy” flow regime according to the Taitel & Dukler Flow regime map, ideal for 2 phase separation. However due to the unfavorable piping, the liquid that should be at the bottom of the piping is swung upwards on the left-hand side in the inlet nozzle, resulting in a massive liquid maldistribution. Inside the inlet nozzle and inlet device, the gas flow is getting grip on this sloshing liquid and is throwing this liquid to the nearby left side vessel wall. The upward flowing gas is pushing the liquids further up the vessel wall. The ship motions are enlarging this undesirable effect and at certain times, the liquids are even entering the meshpad demister causing potential damage to the meshpad and causing potential liquid carry over issues.

SOLUTION:
In this occasion, the solution was simple. Improve the inlet piping and remove the undesirable out of plane bends. If you would like to know more about this typical project or about our independent CFD and Separation expertise, please contact us at [email protected] or visit our website http://kranjisolutions.com.

CFD ANALYSIS BY KRANJI SOLUTIONS: In addition to many applications outside the process industry, for upstream, midstream and downstream Oil & Gas, CFD is an invaluable tool. It offers understanding of phase-interactions and quantifying velocities, forces and phase behaviour in complex flow systems.- Kranji Solutions has over 20 years’ experience assisting service companies and leading process operators to remedy process operation failures and constraints on production. Applying our industry knowledge and modelling skills we also develop unique equipment for our customers where they have challenging production and processing requirements involving 2-, 3- and 4-phase flows. TROUBLESHOOTING AND ANALYSIS Using CFD in combination with MySep separator modelling software (www.mysep.com), or heat exchanger and process modelling, Kranji provides insight into the root cause of mal-performance. Our specialisation in the application of CFD to internal flows, where phase-interaction is key to equipment performance, has resulted in a unique skill profile which has brought us