Process heater control
AssigneeThe Babcock & Wilcox Company
InventorsMarion A. Keyes, IV, Robert E. Pocock
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Abstract
A method for controlling a process heater in which a required heat demand is computed based on the enthalpy of the feed stock and the desired enthalpy of the final product, and then used as a feedforward portion of the fuel control. A second embodiment of the invention is based on the assumption that the feed stock enthalpy changes slowly or infrequently. In this embodiment fuel heating value changes are used as a feedforward portion of the fuel control.
Claims5
A method for controlling combustion in a process heater comprising the steps of computing a heat flow required to produce a desired final product temperature, controlling the position of the heater stack damper as a function of the computed heat flow, calculating the total heat flow of the fuel to the heater, comparing the calculated heat flow with the required heat flow, and trimming the fuel flow to the heater as a function of the difference between the calculated heat flow and the required heat flow.
A method for controlling combustion in a process heater comprising the steps of generating a first trim signal representative of the oxygen content of the heat flue gas, generating a second trim signal representative of the fuel heat flow index, generating a heat flow demand signal based on the product outlet temperature, and controlling the flow of fuel to said heater based on said heat flow demand signal as trimmed by said first and second trim signals.
Dependencies are inferred from the claim text.