Modeling of Water Steam Separation in the Gm-50-1 Boiler Drum Separator
Keywords
Abstract
The paper presents the results of a numerical study of the processes of water vapor separation in the drum-separator of the GM-50-1 boiler unit, performed using the ANSYS CFX CFD package. The computational model takes into account the real hydrodynamic conditions of the drum: the supply of a steam-water mixture from the screen tubes, thermally insulated state of its metal casing, as well as organized selection of saturated steam from the upper part and water from the lower part. The Realizable k–ε model was used to describe turbulence.
The dispersed moisture phase was modeled as a set of spherical particles within the DPM approach, with the calculation of trajectories in the Lagrangian formulation taking into account the inertia of particles, hydrodynamic resistance and gravitational action. The main steam flow was described by the Navier–Stokes equations for a continuous medium. The interaction of droplets with each other was not taken into account. Hydrodynamic and heat exchange processes were modeled according to the Shiler–Nauman and Ranz–Marshall models.
The use of ANSYS CFX made it possible to determine the position of the phase transition zone and the spatial location of the evaporation mirror in the drum, which is of key importance for ensuring stable operation of the boiler unit. In the absence of experimental data regarding local vapor content, the assessment of the model correctness was carried out on the basis of technological requirements for the operation of drums of this type.
The results obtained can be used to optimize design solutions, operating parameters and assess the performance of power boiler drums.
