Boiler control having a heating value computer and providing improved operation with fuels having variable heating values
AssigneeWestinghouse Electric Corp.
InventorLouis P. Stern
Life of this patent
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Abstract
A boiler control regulates the input fuel and air to satisfy load demand. Simultaneously, fuel flow is adjusted by fuel flow control to correct for changes in fuel heating value. A computer circuit which generates a heat balance ratio of outlet steam flow and input mass fuel flow as a representation of imbalance between presumed heat input and actual heat output and by inference from the imbalance or change in fuel heating value. The heat balance ratio is multiplied against an actual fuel feedback signal and the ratio corrected signal is applied to the fuel flow control.
Claims7
A control system for a boiler or other fluid heaters in which inlet fluid is heated to an elevated temperature and pressure, said system comprising means for generating a representation of load on the boiler, means for generating a demand for input fuel and a demand for input air as a function of the boiler load, means for generating respective representations of boiler outlet fluid flow and input fuel flow, means for generating a heat balance ratio of the outlet fluid flow and input fuel flow representations, means for controlling the input flow of fuel to satisfy the fuel demand, means for controlling the input flow of air to satisfy the air demand, and means for correcting one of said controlling means for changes in fuel heating value as a function of the heat balance ratio.
Dependencies are inferred from the claim text.