Two-phase flow phenomena in LNG processes

A main challenge in the design and operation of LNG plants is the heat exchangers. Compact and efficient heat exchangers are needed to obtain an energy efficient plant with low emissions.

The engineering tools in use today are only accurate up to a certain point. More optimized designs require more accurate tools for design and operation. Such tools can only come as a result of an improved physical understanding of the complex two-phase flows occurring in the heat exchangers, something which can be achieved by more detailed mathematical modeling, together with dedicated laboratory observations.

In this sub-project, two-phase flow phenomena in confined geometries are studied both experimentally and numerically. By using a high-speed camera, we study droplet-film interactions in detail and try to characterize the transition between different impact flow regimes for fluids and geometries relevant for compact heat exchangers. In the numerical approach, the Navier-Stokes equations are solved and the level-set method is used to track phase boundaries with great accuracy. By adapting the numerical method to configurations relevant to heat exchangers and verifying it using experimental data, we can gain the insight necessary to develop higher-level models that can be employed for engineering purposes.

One PhD candidate and one postdoc have been educated in this subproject:

He Zhao (postdoc)
An Experimental Investigation of Droplet-Film Phenomena in LNG Systems
Project leader: Professor Jostein Pettersen

Karl Yngve Lervåg (PhD candidate)
Mathematical modelling of two-phase flows and heat transfer in confined geometries
Supervisor: Professor Bernhard Müller
Co-Supervisor: Svend Tollak Munkejord

Droplet falling on a flowing film captured with a high speed camera.

Simulation of two droplets that collide using the level-set method.

Simulation of a droplet colliding with a pool using the level-set method.