Dynamic model and simulation for a high consistency refining process

• A novel dynamic model for the behavior inside of the gap of a high consistency refiner in the pulp and paper industry is presented. As the original entropy model gives additional information about the work split between thermodynamic effects and fiber changes inside the refining zone, it is used as a base for a dynamic model to describe the efficiency of the refining process. This model is derived for the mass flow rates of steam and water, changes of the work distribution and consistency as a function of radius and time. The temperature distribution inside the refining zone, specific energy, inlet consistency and total mass flow rate are used as input signals. After a general presentation in continuous-time, the spatial discrete model is also discretized in temporal dimension. Both discretizations are dependent on each other as the ratio can be considered as a flow speed of the fluid elements and it affects the residence time inside the refining zone. Thereafter, results from a simulation with assumed input parameters using the discrete model are presented and compared with the output of previously published models. Other dynamic models exhibit similar oscillations when applying changes to the inputs. Furthermore, the overall general trend is consistent with other published steady-state models. Hence, we expect the newly proposed model to be reliable and more efficient to describe the behavior inside the refining zone.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Reglerteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Control Engineering (hsv//eng)

Nyckelord

Pulp

Paper

Dynamic Modelling

High Consistency Refiner

Simulation

Reglerteknik

Control Engineering

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)