Patent No.: 8,230,825 (get PDF)

Title: Boiler control system

Assignee: Knorr, Jr.; Warren G.

Abstract: A boiler control system for efficiently controlling the operation of a packaged boiler is provided. The system includes a combustion air control system, a fuel control system, a flue gas sensing system, and a boiler controller. The boiler controller is in operative communication with the combustion air control system, fuel control system, and the flue gas sensing system. Based upon a system demand, the boiler controller controls coarse-level operation of the combustion air control system and the fuel control system. The flue gas sensing system includes an oxygen sensor and a flue gas differential sensor that senses a change in a characteristic of the flue gas. When the flue gas differential sensor senses a change in the flue gas characteristic that meets a flue gas differential setpoint, the boiler controller controls fine-level operation of the combustion air control system to efficiently control the amount of oxygen in the flue gas.