Recuperator model for glass furnace reburn analysis

• Main Author: SHELDON; MARK S
• Format: Patent
• Language: English
• Published: 09.06.1998
• Edition: 6
• Subjects: CONTROL OR REGULATING SYSTEMS IN GENERAL; CONTROLLING; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS ORELEMENTS; PHYSICS; REGULATING

A method and system for modeling the behavior of a recuperator in a furnace determines the mass flow rate and enthalpy flow rate for each gas stream within a furnace based on an initial set of operating conditions and parameters. Based on the mass flow rate and change in enthalpy flow rate for each gas stream in the recuperator, the amount of heat transfer in the recuperator is derived and the exit temperatures of primary air and exhaust gas are revised in an iterative fashion. The iterative process continues until revised exit temperatures differ from one iteration to the next by less than a predefined tolerance. The heat transfer in the recuperator is determined using the product of an overall heat transfer coefficient and the log mean temperature difference calculated from the inlet and outlet temperatures of the primary air and the inlet and outlet temperatures of the exhaust gas. The mass and energy calculations are performed with the revised set of temperatures followed by another determination of the amount of heat transfer in the recuperator. The process continues in this iterative fashion until mass and energy results throughout the furnace change from iteration to iteration by less than a predefined tolerance. The method can be used to indicate variations in furnace behavior due to a change in one or more parameters an operating condition, or a process variation such as the addition of reburning. The mass flows within the furnace are automatically adjusted to accommodate returning in the furnace.