Analysis and optimization of heat loss for water-cooled furnace roller

Abstract

A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller’s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The model is proved logical and credible by comparing calculated results and measured data. Then, the relationship between water flow velocity, inlet water temperature, furnace temperature and roller cross section temperature, outlet water temperature, water temperature rise, cooling water heat absorption was studied. The conclusions and recommendations are mainly as follows: 1) Cooling water temperature rise decreases with the increase of water flow velocity, but it has small relationship with inlet water temperature; 2) In order to get little water scale, inlet water temperature should be controlled below 30 °C. 3) The cooling water flow velocity should be greater than critical velocity. The critical velocity is 0.07 m/s and water flow velocity should be controlled within 0.4–0.8 m/s. Within this velocity range, water cooling efficiency is high and water temperature rise is little. If cooling water velocity increases again, heat loss will increase, leading to energy wasting.