Temperature Control of a Continuous, Push-Type, Five-Zone, Slab-Reheating Furnace for Minimum-Fuel Usage. Volume I. Text and Appendix A

摘要

Investigations are made of temperature control for a continuous, five zone, pusher type, reheat furnace used to heat slabs from the slabbing mill up to the rolling temperature needed for the hot strip mill. Minimum fuel rates needed to achieve required outlet temperature as a function of production rate are determined. A scheme is presented for carrying out the transition from one steady state operating level to another with a near minimium of fuel usage. A method for using this transition scheme on a process control computer is also presented. A specific objective of this thesis is to suggest a control algorithm for temperature control that minimizes the amount of every consumption during production while that production is subject to various process variations and constraints. Chapter II describes the slab reheat furnace model used for the study. A list of model embellishments and detected errors are presented in addition to the steady state energy balance analysis of the model itself. Chapter III presents the three separate cases of furnace operation and their steady state configurations for eight operating points. Transitions from one of these operating points to another operating point is discussed in Chapter IV. This serves as a basis for the control strategies discussed in Chapter V. The last chapter summarizes the results and conclusions of the study and suggests recommendations for future work. Appendix A includes additional simulation results supplementary to those presented within the report text. Model documentation and computer program listings are presented in Appendix B, C, and D, presented in Volume II. (ERA citation 06:030870)