A NOVEL, INTELLIGENT AND COST-EFFECTIVE COMBINED COMBUSTION CONTROL SYSTEM

摘要

Conventional control systems like parallel type air-fuel combustion control and cross-limiting type combustion control techniques have been found to suffer from drawbacks like (a) incomplete combustion problem, (b) boiler stuck-up problem and (c) boiler bump problem. The present invention effectively overcome the above drawbacks by providing a novel, intelligent and cost-effective combined combustion control system, employed in industrial power generation, comprising in combination: a. a calculation block CAL 305 (1), specifically developed for the application; b. a ratio bias controller HIC 301 (2), that transmits steam demand signal to (1); c. a fuel flow transmitter FT 308 (3), that transmits fuel flow signal to (1); d. an oxygen analyzer AIT 303 (4), that transmits actually measured percentage of oxygen in flue gas signal to (1); e. a piecewise linear input block PLI 301 (5) that transmits the desired percentage of oxygen signal to (1); f. an airflow transmitter FT 305 (6) that transmits air flow signal to (1); g. another piecewise linear output block PLI 305 (7) that transmits signal from the output of the calculator block (1); h. a low signal selector FY- Lo (8), that receives signal from (7) and actuates parallel type combustion control for small steam demand variations or cross-limiting type combustion control for large steam demand variations.