Simulation of a fish freezing tunnel using Modelica

The problem of energy consumption during freezing of pelagic fish in an air blast freezing tunnel was investigated. Measurements from a freezing plant were compared with the results from a simulation model, and the results of the comparison show that the required freezing time can be reasonably well predicted. The simulation results show that the freezing time is strongly depending on the type of product and fat content of the fish that is being frozen. Fish filets with 20% fat content require 11% shorter freezing time than fish filets with 7% fat content, and round fish require 16% shorter freezing time than fish filets. Energy can be saved by taking this into account when operating the freezing tunnels.