Boiler control providing improved operation with fuels having variable heating values
AssigneeWestinghouse Electric Corp.
InventorLyle F. Martz
Life of this patent
Estimating the term…
Abstract
A boiler control regulates the input fuel and air to satisfy load demand. Simultaneously, the air flow is adjusted by an air flow control to correct for changes in fuel heating value by means of a circuit which operates in response to outlet steam flow and input mass fuel flow to determine the difference in presumed heat input and actual heat output and, by inference from the heat imbalance or error, a change in fuel heating value. The heat error is used to adjust the air flow demand to the air flow control. In another embodiment, boiler heat pickup is derived to remove from the heat imbalance any heat input changes other than fuel heating value changes.
Claims15
A control system for a boiler or other fluid heater 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 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 outlet fluid flow and input fuel flow representations.
Dependencies are inferred from the claim text.