Boiler automatic control system

Abstract

Abstract PURPOSE:To perform the operation with a stable low NOX emission by controlling the damper opening by feeding back the NOX level signal from an NOX analyzer to a W/B inlet damper control circuit, and adding a correction to the air/fuel ratio master, depending upon the variation in fuel constituents. CONSTITUTION:A determination is made as to whether or not the NOX level is exceeding the regulatory standard, and if over the standard, a correction signal is prepared by comparing the NOX level from an NOX analyzer with the NOX level determined by the boiler performance. Likewise, depending upon the mixed burning factor determined by the constituents of fuel and the kind of fuel, a correction signal is prepared by comparing with the NOX level determined from the boiler performance. Next, a determination is made as to whether the boiler is an in-furnace denitration boiler or a multi-fuel burning boiler, and if it is an in-furnace denitration boiler, the air/fuel ratio for respective boiler stages is adjusted by corrective the NOX master signal. If it is a multi-fuel burning boiler, the W/B air quantity for respective boiler stages is adjusted. In this manner, the opening of the W/B inlet damper is adjusted and corrected to provide the optimum air/fuel ratio for a low NOX operation.

Inventors

• 👤 Mitsuo Tanaka
• 👤 田中　三雄
• 👤 Akira Sugano
• 👤 彰 菅野
• 👤 Atsushi Esashi
• 👤 厚 江刺
• 👤 Kiyoichi Sato
• 👤 佐藤　喜代一
• 👤 Shinya Kikuchi
• 👤 信也 菊池

Bibliographic Details