초록 ▼

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

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 may include an oxygen sensor and a flue gas differential sensor to sense 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 the fine-level operation of the boiler.

대표청구항 ▼

1. A boiler control system for controlling the operation of a boiler (100), comprising: A) a combustion air control system (200) including a combustion air fan (210) for supplying combustion air to the boiler (100);B) a fuel control system (300) including a burner (310) for supplying fuel to the boi

1. A boiler control system for controlling the operation of a boiler (100), comprising: A) a combustion air control system (200) including a combustion air fan (210) for supplying combustion air to the boiler (100);B) a fuel control system (300) including a burner (310) for supplying fuel to the boiler (100) and a fuel valve (320) for controlling the amount of fuel supplied to the boiler (100) by the burner (310);C) a flue gas sensing system (400) including a flue gas differential sensor (420), wherein the flue gas differential sensor (420) senses a change in a predetermined characteristic of the flue gas associated with a change in the combustion air control system (200); andD) a boiler controller (500) having a system demand setpoint (510) and a flue gas differential setpoint (530), (i) wherein the boiler controller (500) is in operative communication with the combustion air control system (200), the fuel control system (300), and the flue gas sensing system (400), and(ii) wherein the boiler controller (500) controls coarse-level operation of the combustion air fan (210) and the fuel valve (320) based upon the system demand setpoint (510), and(iii) wherein when the flue gas differential sensor (420) has sensed a change in the flue gas predetermined characteristic that meets the flue gas differential setpoint (530) the boiler controller (500) controls the fine-level operation of the boiler. 2. The boiler control system of claim 1, wherein the flue gas differential sensor (420) is a temperature sensor (422) measuring the temperature of the flue gas and the flue gas differential setpoint (530) is a predetermined change in flue gas temperature. 3. The boiler control system of claim 2, wherein the predetermined change in flue gas temperature is a temperature change of at least 2% and is sustained for at least 2 seconds before the fine-level operation of the boiler begins. 4. The boiler control system of claim 1, wherein the flue gas differential sensor (420) is a flowrate sensor (424) measuring the flowrate of the flue gas and the flue gas differential setpoint (530) is a predetermined change in flowrate of the flue gas. 5. The boiler control system of claim 4, wherein the predetermined change in flue gas flowrate is a flowrate change of at least 5% and is sustained for at least 2 seconds before the fine-level operation of the boiler begins. 6. The boiler control system of claim 1, wherein the flue gas differential sensor (420) is a pressure sensor (426) measuring the pressure of the flue gas and the flue gas differential setpoint (530) is a predetermined change in flue gas pressure. 7. The boiler control system of claim 6, wherein the predetermined change in flue gas pressure is a pressure change of at least 5% and is sustained for at least 2 seconds before the fine-level operation of the boiler begins. 8. The boiler control system of claim 1, wherein the flue gas differential sensor (420) is a particulate sensor (428) measuring the amount of particulate in the flue gas and the flue gas differential setpoint (530) is a predetermined change in amount of particulate in the flue gas. 9. The boiler control system of claim 1, wherein the combustion air fan (210) includes a fan speed controller (212) to vary the speed of the combustion air fan (210) to adjust the amount of combustion air supplied to the boiler (100) by the combustion air fan (210). 10. A boiler control system for controlling the operation of a boiler (100), comprising: A) a combustion air control system (200) including a combustion air fan (210) for supplying combustion air to the boiler (100);B) a fuel control system (300) including a burner (310) for supplying fuel to the boiler (100) and a fuel valve (320) for controlling the amount of fuel supplied to the boiler (100) by the burner (310);C) a flue gas sensing system (400) including an oxygen sensor (410) and a temperature sensor (422), wherein the oxygen sensor (410) senses the amount of oxygen in the flue gas leaving the boiler (100) and the temperature sensor (422) measures the temperature of the flue gas; andD) a boiler controller (500) having a system demand setpoint (510), a flue gas oxygen setpoint (520), and a flue gas differential setpoint (530) set at a 2% change in flue gas temperature, (i) wherein the boiler controller (500) is in operative communication with the combustion air control system (200), the fuel control system (300), and the flue gas sensing system (400), and(ii) wherein the boiler controller (500) controls coarse-level operation of the combustion air fan (210) and the fuel valve (320) based upon the system demand setpoint (510), and(iii) wherein when the temperature sensor (420) has sensed a change in flue gas temperature that meets the flue gas differential setpoint (530) and the change is sustained for at least 2 seconds, the boiler controller (500) controls the fine-level operation of the combustion air fan (210) to maintain the flue gas oxygen setpoint (520) based upon the amount of oxygen in the flue gas sensed by the oxygen sensor (410). 11. A boiler control system for controlling the operation of a boiler (100), comprising: A) a combustion air control system (200) including a combustion air fan (210) for supplying combustion air to the boiler (100);B) a fuel control system (300) including a burner (310) for supplying fuel to the boiler (100) and a fuel valve (320) for controlling the amount of fuel supplied to the boiler (100) by the burner (310);C) a flue gas sensing system (400) including an oxygen sensor (410) and a flowrate sensor (424), wherein the oxygen sensor (410) senses the amount of oxygen in the flue gas leaving the boiler (100) and the flowrate sensor (422) measures the flowrate of the flue gas; andD) a boiler controller (500) having a system demand setpoint (510), a flue gas oxygen setpoint (520), and a flue gas differential setpoint (530) set at a 5% change in flue gas flowrate, (i) wherein the boiler controller (500) is in operative communication with the combustion air control system (200), the fuel control system (300), and the flue gas sensing system (400), and(ii) wherein the boiler controller (500) controls coarse-level operation of the combustion air fan (210) and the fuel valve (320) based upon the system demand setpoint (510), and(iii) wherein when the flowrate sensor (420) has sensed a change in flue gas flowrate that meets the flue gas differential setpoint (530) and the change is sustained for at least 2 seconds, the boiler controller (500) controls the fine-level operation of the combustion air fan (210) to maintain the flue gas oxygen setpoint (520) based upon the amount of oxygen in the flue gas sensed by the oxygen sensor (410).